The Foundation of Moral Reasoning: The Development of the Doctrine of Universal Moral Principles in the Works of Thomas Aquinas and his Predecessors

One of the most important topics in moral theory considers the foundation for universal principles of conduct that pertain to every society and every age. The legacy of Platonic thought includes the idea that certain practices were eternally ordained by divine beings and are therefore universally binding. Another position, however, represented best by the works of Aristotle establishes moral excellence on the actions of the best citizens within a particular society. Both traditions influence moral thought in the thirteenth century, but the medieval masters ultimately chose the first alternative, and argued that all morally good decisions must be in accord with universal commands that are the expression of the natural law and are recognized by an innnate human power. The notions of natural law, divine law and the ability to recognize their principles, which the medieval theologians called synderesis, distinguish Christian moral speculation from Aristotle's practical philosophy despite his enormous influence upon subsequent ideas, such as human goodness, the nature of virtue and moral weakness, which were discussed extensively in the later age.

Plato provided a measure when he concluded that every object and act should be judged according to a universal and eternal standard. Since nothing in the material world could qualify as such a paradigm, the Platonic measure is divine and transcendent. All objects in their being and intelligibility are related to the immaterial divine forms. A universal concept, such as beauty itself, which few modern thinkers would consider real, is a true being in its eternal form, and the standard by which all inferior beautiful objects may be measured. In the Symposium Socrates relates the story of his philosophical education directed by Diotima, a wise woman of Mantinea, who teaches him the connection between true beauty and the derived manifestations of it in the material world. Anyone who has regarded beautiful things properly will become aware of something wondrous that provides meaning to all former efforts at understanding the nature of beauty. If one contemplates beauty's common element one gains a unified understanding of beauty itself.^[1] The intuition that such perfect beauty exists recognizes its true nature as everlasting, immutable and universal. It is beauty absolute, separate, simple, everlasting and entirely unchanged by objects that gain their beauty by participation in it.^[2] Rather than merely considering the form an objective metaphysical and epistemological unifying element, Diotima extends its relevance to the moral realm:

This, my dear Socrates... is that life above all others which man should live in the contemplation of beauty absolute... But what if man had eyes to see the true beauty–the divine beauty, I mean, pure and clear and unalloyed, not clogged with the pollutions of mortality and all the colors and vanities of human life... Remember how in that communion only beholding beauty with the eye of the mind, he will be enabled to bring forth, not images of beauty but realities... and bringing forth and nourishing true virtue to become the friend of God and be immortal, if moral man may.^[3]

Whatever Plato's final doctrine concerning the separate existence of forms turned out to be,^[4] he retained always the Socratic ideal of a divine model and the quest for the soul's immortality as the basis for moral decisions.

For Socrates and Plato the truly good person is one

[…] born to arrive towards reality, who cannot linger among that multiplicity of things which man believes to be real, but holds on his way… until he has laid hold upon the essential nature of each thing with that part of his soul which can apprehend reality because of its affinity therewith; and when he has by that means approached real being and entered into union with it… so that at least having found knowledge and true life and nourishment, he is at rest from his travail.^[5]

The entire thrust of Socratic ethics is to direct human beings away from the imperfections of the world and toward a perfect existence that culminates with a union of the intellective soul with the perfect objects of knowledge, the forms. When responding to a question concerning “the fair measure of truth” Socrates responds: “No measure that falls in the least degree short of the whole truth can be quite fair in so important a matter. What is imperfect can never serve as a measure; though people sometimes think enough has been done and there is no need to look further.”^[6] The perfect measure is applied to moral action when Socrates argues in the Theaetetus:

God is supremely just and what is most like him is the man who has become just as it lies in human nature to be... There are two patterns set up in the world. One is divine and supremely happy; the other has nothing of God in it, and is the pattern of the deepest unhappiness. This truth the evildoer does not see.^[7]

The measure of human goodness is divine and those who are to become happy recognize the basis for moral actions and those who do not accept the divine foundation cannot become truly good. Plato's divine pattern in the world serves as the moral paradigm for everyone. Plato's ethical theory may seem too demanding for modern readers who may judge his moral goals so lofty that “no one can in fact achieve them”.^[8] Plato, himself, seems untroubled by the loftiness of his standards as he indicates in the Republic. When Glaucon doubts that the republic described by Socrates could exist anywhere on earth, Socrates agrees, but reminds Glaucon of the pattern in heaven for anyone who wishes to see it and model actions upon it. Whether it actually exists, or will ever exist on earth, does not trouble Socrates at all.^[9]

The enduring message of Platonic moral theory lies in its acceptance of an eternal standard that serve as universal models of right action. While they are ultimately unattainable during a human lifetime, they direct all toward a universally applicable standard of conduct.^[10] Plato does not think that the importance of the form is lost by the human need to adapt customs and laws to political needs.^[11] His “solution to the problem of objectivity is given... by the theory of forms. The form of justice is common to all that we describe as just... and it also provides the standard to which we must refer in judging the rightness of conduct as well as legislation.”^[12]

Like many of Plato's doctrines the notion of immutable universal moral standards provoked a critical reaction from Aristotle. Aristotle makes the final arbiter of moral rectitude not divinely inspired models but the reasoned choices of the practically wise person. While those seeking precise moral formulations will become disappointed in their search through Aristotle's works, he would himself remind them not to seek more precision than their investigation allows. Aristotle recognizes the importance of circumstances, customs and individual talents that enter into all moral actions. His ethics tends toward a reasoned conservatism since he places great faith in the ability to construct a rational and effective moral tradition. He recognizes that even if Plato's proposed social innovations may in theory improve society, they constitute little more than philosophical musings, since they had no possibility of implementation.

Both Plato and Aristotle recognized the flexibility and mutability of human moral goodness, but they did so in different ways. Plato posited eternal standards by which all beings may be known and judged, but recognized the limitations of human beings to reach these standards. Aristotle, however, described certain universal laws as applicable to all political states (EN 1134b17–30), but G. Striker observes that Aristotle also held that the practically wise or decent person's decisions would be objectively right though they do not result from the application of fixed rules.^[13] The phronimos has far more freedom in Aristotle's ethical theory than the just person in Plato's theory, since practical wisdom extends to the entire range of human decisions. While murder and fraud may be universally proscribed, the phronimos determines when killing and deception may be considered good, especially in service to a nobler end. The wise person may arrange an individual life in the way that best leads to goodness for oneself and others.

While Plato provided the philosophical foundation for an immutable standard of conduct, Cicero is the primary source of this idea in medieval philosophical and theological works. The notion of an eternal ethical standard, expressed succintly as the natural law forms an integral part of Stoic philosophy.^[14] The notion of natural law depends upon a perceived harmony between correct human practices and a natural order governed by a providential deity. For Cicero true law is right reason in accordance with nature, and it is constant, eternal and universally applicable. No one may alter this law, repeal any part of it, or abolish its commands entirely. Neither the senate nor the people may free human beings from natural law. Cicero claims there cannot be one law in Rome and another in Athens, but rather one law for all people now and in the future. The author and judge of this law is God himself, whose commands compel obedience. Cicero asserts that anyone who rejects this law flees from oneself (se fugiet) and spurns his own nautre.^[15] Although these ideas are expressed by Laelius, they clearly represent Cicero's own views.^[16] Law, which distinguishes justice from injustice, originates in agreement with the most ancient ruler of all things, nature. All human laws must be derived from this standard in order to be just.^[17] Human beings come to recognize the natural law as supreme reason, which is implanted in nature (insita in natura) and issues commands and prohibitions. Since this law is constant in the human mind, learned men believe it to be wisdom (prudentiam), which has the power (vis) to comand correct action and to forbid incorrect conduct. In the De legibus Cicero often refers to this natural law as a force, and once specifies it as the mind and the reason of the wise man (ea est enim naturae vis, ea mens ratioque prudentis).^[18] While not exactly clear about the distinction between the law itself and the human power to recognize it, Cicero has provided the foundation for the medieval concept of natural law. As is clear from what follows, medieval authors accepted the notion of the law of nature and specified the power (vis) by which its principles are recognized as synderesis.

While one might argue that the natural law may be reduced to the general command to do good and to avoid evil, Cicero provides a list of specific duties in the De officiis. They include the basic biological obligations for self-preservation, reproduction and care of the young. Because nature endows human beings with reason and speech further duties arise from these abilities. The power of reason allows for common bonds among people which lead to political organizations and efforts to satisfy desires within the household and in the community. Above all other duties are the quest for truth, and the exercise of the independence of mind, all of which constitute the highest human pursuits in accord with nature, and this hierarchy of natural endeavors leads necessarily to a blissful life (ad beate vivendum necessarium ducimus).^[19] Cicero certainly recognizes various practices within different societies and distinct talents in human beings. In considering the origin and sources of laws he concludes that true law is derived always from nature, but certain principles become custom by reason of their utility. When such principles are tested by practice and accepted as truly useful, they are confirmed in statutes. Cicero here unites the two traditions of legal and moral principles by accepting universal laws of nature while also recognizing how specific decrees derived from nature may be adapted to suit societal practices.^[20]

The task of interpreting the imperatives of natural law does not fall to anyone, but rather to the wise person, who guides both individuals and societies. Cicero accepts the idea that divine laws need explication from one who is truly wise. Like the Aristotelian phronimos, the Ciceronian sapiens must follow the path of his own nature, but for Cicero the sapiens has the guidance of absolute universal principles, even if the wise person may adjust for specific practices to fulfill particular needs. While Aristotle's measure is always human, Cicero adds a divine element.^[21] In a passage reminiscent of Aristotle's praise for the phronimos' ability to attain moral goodness, Cicero writes: “And so moral goodness, when designated truly and properly, is in wise persons only and cannot even be separated from virtue.”^[22] Cicero reaches here the critical point in ancient moral theory, but as he often does, he provides no philosophical resolution to the question.^[23] Cicero has the opportunity here to explain the way in which a wise person may adjust and adapt universal codes to suit particular societal and individual demands, but he concludes merely with an appeal to the Stoic concept of the sapiens: “But that duty which the same <Stoics> called right, perfect and absolute, and which they said hits the numbers is beyond anyone except for the one who is wise...”^[24]

Cicero may not have realized how close he came to unifying the eternal standard of the Platonists with the human moral model of the Peripatetics, but he did provide the foundation to medieval authors for their concept of eternal natural law. It is hardly surprising that the first extensive treatment of this idea appears in the treatises of the canonists in the late twelfth century. In the thirteenth century the science of ethics, infused with the recently translated texts of Aristotle and stimulated by the deliberations of canonists, considered moral questions on virtue, law and human purpose in a manner open to solutions that went beyond traditional religious answers. While the authors of the early thirteenth century did not challenge Christian authorities they were able to see a variety of new approaches to moral problems. William of Auxerre, who was one of the ecclesiastical authorities chosen by Pope Gregory IX in 1231 to examine the works of Aristotle,^[25] remained primarily influenced by Scripture and the works of Augustine, but is willing to use the conclusions of Aristotle and the canonists when they are helpful in moral matters. William's Summa aurea contains extensive treatments of theological ideas discussed at Paris in the first half of the thirteenth century. Based primarily on Peter Lombard's Sentences his discussions include topics in moral theology, such as natural law, beatitude and the cardinal virtues. In this work William makes use of the translation of Aristotle's Nicomachean Ethics (NE) that had appeared in the twelfth century.^[26] The Summa's short section on natural law, which O. Lottin calls the first theological treatment of the question,^[27] appears immediately after the treatment of the cardinal virtues, and contains William's assertion that “natural law is the origin and principle of all virtues and their motions.”^[28] Like his contemporaries, William begins with Augustine's basic premise that “the eternal law is prior to every principle of order, the work of ordaining reason.”^[29] The canonists had also provided a distinction within the idea of natural law that William finds useful: natural law may be understood broadly or strictly. Taken in the first way, natural law teaches all living beings certain practices, such as the union of male and female. In this understanding of natural law there is no consideration of vice or virtue. Taken strictly, natural law denotes how natural reason dictates without any, or without great deliberation, what should be done, such as God is to be loved.^[30] In the strict sense of natural law William can hardly find a basis for moral judgments about right and wrong.

Like other later medieval authors who view a passage in book V of the NE as evidence for an Aristotelian doctrine of natural law, William also finds this concept in Aristotle's philosophy. Because he was not familiar with the fifth book of the Ethics, William, however, identifies the source for Aristotle's concept of natural law to be Topics (119a16-17). William understands the argument that what has a quality naturally must have it to a greater degree than what does not have it naturally, as an indication that what is just according to natural law must be more just than what is merely asserted by positive law. That which is generally just is so because of natural law.^[31] William does not make further use of this passage from Aristotle, and bases most of his conclusions on the subject from Christian sources. He credits Prepostinus for identifying different categories within the general concept of natural law, such as precepts, prohibitions and demonstrations. The only specific precept mentioned is the golden rule, and the primary prohibition expresses this very same rule negatively. The decalog also contains examples of prohibitions that reflect the force of natural law. Demonstrations merely identify external conditions, such as the command to the Apostles to refrain from answering force with force.^[32]

In the section on natural law William does not refer explicitly to the idea of synderesis, but implies a connection between the two concepts when he asks how natural law may be written in the human heart. William is not the first to make the connection between natural law and the principles of synderesis, since a decretist, Simon de Bisiniano, had done so in the twelfth century.^[33] In his solution William ignores the connection of natural law to prudence, and merely indicates that the human soul naturally has a vision of “first goodness” (primam bonitatem).^[34] Later in this Summa he connects the precepts of natural law to those of synderesis. William understands the admonition in Isaiah to liars to return to the heart, in which the law is written, as an implicit reference to synderesis. In the heart, he says, is synderesis which commands what is to be done and what is to be avoided. This ability is a norm of reason, or the conformity to divine will, which informs the commands of prudence.^[35] William refers again to the same passage when he considers the state of sinners' souls. There he argues that these souls are only partially weakened. One part that is synderesis, as the superior part of reason, remains healthy since it cannot sin. It can never judge evil to be good and always rejects evil. The lower part of reason may judge good to be evil, but synderesis with its infallible understanding remains untouched by error.^[36]

Unlike authors later in the thirteenth century William makes no effort to determine the nature of synderesis as a potency or habit. He is content to identify it merely as the superior part of reason, whose primary function is to command a human being through free choice to seek true delight or beatitude. In this way he indicates that synderesis functions as a power of will. As a voluntary power it does more than merely display what is right through reason.^[37] Here William displays his obvious difficulty in determining the precise function of synderesis, and also in deciding whether it is part of the will or reason. He, like his contemporaries, demonstrates further confusion concerning the exact nature of the virtue of prudence. He begins his discussion of the cardinal virtues by asserting their function to enable human beings to attain the theological virtues by exterior acts which make them similar to God.^[38] In passages specifically devoted to the virtue of prudence William asks whether it may be identified with the moral science that is found in the book of Solomon and in the Ethics of Aristotle. These works claim that its primary function is to guide one in the choice of good over evil.^[39] William continues by dividing the judgments of reason into one of discretion, which knows what to do, and into one which is definitive and commands what is to be done. He says here that prudence differs from moral science because the latter merely indicates what to do, but prudence orders the proper action. He has very quickly answered the question whether prudence is merely science or knowledge.^[40]

The moral theologians of the early thirteenth century accept the intellectual nature of prudence as an important aspect of human morality, since it must recognize the proper principles of action before it can exercise its moral imperative function. William calls prudence a specifically unique virtue, and not merely science, because it must decree actions according to the dictates of reason. According to William, the ability to align all actions to the norm of reason harmonizes prudence with the divine will.^[41] Another type of prudence that of the spirit is a kind of knowledge that supposes all that is knowable and useful for salvation. This 'gift' of prudence allows its possessor to act frequently in accord with its decrees.^[42] Like many medieval authors William notes the dual nature of the virtue of prudence and recognizes both its intellectual character as a type of knowledge as well as its moral function in the abiltiy to command proper actions.

The goal of all human moral action is beatitude, which may be viewed as either perfect or imperfect. William does not cast this distinction in terms of theological and philosophical considerations. Rather he views imperfect beatitude in its relation to ultimate perfection and notes that the saints will have in the future what they possess presently only imperfectly. Perfect beatitude conveys the satisfaction of every desire with respect to both the present and the future. The saints who attain imperfect beatitude do not actually possess the glory and satisfaction of every desire that they will eventually enjoy.^[43] William makes no effort to define the philosophical concept of happiness or the rational attainment of imperfect beatitude through moral and intellectual virtues. He also ignores the more difficult question of the relation of imperfect to perfect beatitude that many of his successors later in the century will examine at great length.

Philip the Chancellor’s Summa de bono, written c. 1225–1228, is the first comprehensive treatment of moral topics in the thirteenth century. Although Philip states that his primary intention is to investigate goodness theologically, he examines at length philosophical ideas such as the meaning of prudence and synderesis and the composition of moral choice.^[44] Throughout his Summa Philip displays a willingness to consider non-Christian sources when fitting, but his most important non-scriptural source remains the work of Augustine. Even if Philip considers moral ideas that may be viewed as primarily philosophical, his ultimate aim is always theological, since his intent is to identify those acts that ultimately lead one to God.^[45]

In the question on the human powers that allow for free choice Philip distinguishes sharply the powers of motivation within the soul, i.e. will and desire, from synderesis. Synderesis, which is a component of the superior part of the soul, directs human judgments toward goodness and away from evil. Free choice, which draws upon the powers within the lower part of the soul, is flexible with regard to both good and evil. Philip considers free choice to be in a certain manner ‘concupibiscibility’ in the young and concupiscence, or the stimulus to sin, in adults. He distinguishes free choice, which seems to be inclined to moral error, from the natural will. Natural will encompasses deliberative will, which is described as a certain synderesis and choice that proceeds from a prior judgment.^[46] Unlike many of his contemporaries in the thirteenth century, Philip identifies the will (voluntas naturalis) and synderesis, which, as Lottin notes, will lead to Bonaventure's concept of the synderesis as the will's natural inclination (naturale pondus voluntatis).^[47] Free choice is a potency, as is synderesis when it functions in relation to free choice. When a specific choice (proheresis) is made, synderesis is better understood as a habit. Philip regards free choice (liberum arbitrium) and synderesis as general components to moral decisions, but he limits proheresis to an immediate decision. Regulated by a developed sense of right and wrong, synderesis is distinguished from free choice in that it naturally is moved to goodness, while choice may be attracted to evil. Synderesis differs from immediate choice (proheresis) in that it is a natural judgment concerning good, while proheresis is a deliberative judgment.^[48]

Philip considers specifically the notion of synderesis in the question concerning its presence in the souls of angels. There Philip describes synderesis as an integral component to every moral choice. He cites Jerome’s definition of synderesis as the spark of conscience never extinguished, but does not accept completely the identification of synderesis with a spark within the soul. He argues that this spark may be understood either with respect to the intellect or to desire. The spark may be considered in both ways, not only in free choice, but also in the function of synderesis. Philip asks whether this power could ever be extinguished even in the devil. After the fall the devil still would wish to exist without pain and would naturally desire supreme beatitude. This natural desire would always endure.^[49]

In the question devoted to the nature of synderesis, Philip asks whether it should be considered as a potency within the soul or a habit existing naturally within the soul. Although the form of its name seems to indicate that synderesis is a habit rather than a potency, Philip prefers the designation of habitual potency. This power should be considered innate, and not one attained through activity. By its nature as potency it differs from the usually developed habits, and by nature of habit it differs from the normally undeveloped potency. According to N. Wicki, this designation of synderesis as a habitual potency allows Philip to move away from the usual classification of synderesis as understanding and closer to that of will.^[50]

Like many of his contemporaries Phillip seems to have difficulty with the concept of an innate habit. Habits normally require the exercise of activities that develop into a habitual state. Synderesis, while inhering naturally within every human soul, does not regulate actions until a number of moral decisions have been made. By reason of its potency synderesis differs from free choice and sensuality; by its nature as habit it can be distinguished from choosing and desire.^[51] Philip indicates that his position is a compromise concerning the nature of synderesis, which is very similar to natural will. He seems to regard synderesis as one element within the natural will, which extends to rational, natural and subsistent goods, but synderesis is limited to considering rational goods only.^[52]

One may well ask whether synderesis should be considered the same power as free choice or reason. In his arguments against the identification of synderesis with choice and reason, Philip mistakenly cites Gregory as support for his denial of such identification. In reality he uses Jerome’s commentary on Ezechiel 1, 1 to argue for the separate existence of a fourth power within the soul that corrects errors; this power is synderesis.^[53] In his resolution to the question Philip claims that reason can be understood broadly so that it may encompass every moving power of the rational soul, but differs from the soul itself, which is the principle of life. When reason is understood most generally synderesis may be considered as one of its parts.^[54] If reason is taken generally, it will also include the desirous and irascible elements within the human being. Synderesis would also fall under the general abilities of reason as an element capable of intellectual comprehension. If, however, reason is considered distinct from desirous and irascible elements, then synderesis will be viewed as part of the unerring powers that Adam possessed in a state of innocence. It remains as a modest light leading to God in order to prevent human reason from being wholly inclined or twisted to the pursuit of temporal goods. While the rectitude of grace was wholly lost through sin, Adam retained a natural righteousness concerning judgment, will and anger. This rectitude was never completely lost by human beings, and what remains as innate correctness may be called synderesis.^[55]

Philip gives to synderesis more extensive powers than do theologians later in the thirteenth century. In addition to directing one to pursue good and avoid evil, it promotes the proper contemplation of, and the desire for, the good simply. Synderesis functions also as the critical examining faculty (inspectrix) of all things in relation to the supreme good, to which it is principally related. In this way synderesis is not a potency apart from the other moving powers of the soul that consider good and evil, but remains steadfastly joined to them in the pursuit of goodness.^[56] In extending the domain of synderesis to include the arrangement of good with respect to the supreme good, Philip elevates it to a supreme moral power. Not only does it allow one to attain moral virtue, but it also directs all one’s activity to God. Philip thereby makes it an essential element in the acquisition of imperfect or perfect beatitude. He asserts that it is nobler than all the other powers of the soul because of its inflexible adherence to the desire for good and its aversion to evil. Philip would place synderesis above reason and in the understanding, if understanding signifies that which leads to supreme goodness without considering particular goods in actions. Reason may be judged as correct or incorrect with respect to specific acts of good and evil, and at times may be subject to the imagination which arises from goods comprehended through sense experience. If reason is thought to be affected by imagination, then synderesis is more properly thought to exist beyond reason.^[57] In elevating synderesis above reason, Philip can preserve the infallibility of its dictates, while simultaneously accepting the possibility of moral error. Philip is untroubled by the lack of a concept of synderesis in the moral writings of Aristotle.

In resolving the question concerning the manner by which synderesis leads one to reject evil, Philip concludes that it moves free choice by prescribing good and preventing evil. It also moves the choice toward a common good that is found in all particular good choices, but does not move one to choose common goodness in itself.^[58] Synderesis is not characterized by a deliberative judgment, but rather by one that leads to action. Both natural will and synderesis are directed to natural goods, but in different manners. Natural will is like a potency, but not a habitual one like synderesis. The will may be directed toward other goods, whereas synderesis leads only to those objects good by nature. Both cognition and desire move the natural will, while an intellectual process of cognition alone governs synderesis.^[59] Philip designates synderesis a habitual potency not because it may be frustrated in itself, but because it may be impeded by disobedience to reason. An act of judgment under difficult circumstances may prevent the full exercise of reason.^[60]

Synderesis has a close connection to the natural will, since they are the same in subject, but they differ in that natural will is only a simple potency. Natural will, therefore, may err in judgment, but synderesis, as a natural potency cannot do wrong through its own power.^[61] Philip’s second argument declares that the soul in itself is eternally punished for sin, which is the product of the moving powers. He notes that conscience, which Gregory identified with synderesis, may produce error, and may not be an infallible guide to right and wrong actions. If synderesis were such a motivating force, it would also be a source of error and sin. He argues further that contraries arise in the same power and since virtue and vice are contraries, they must originate in the same potency. Virtue, which is the gift of wisdom, would arise from the supreme power of the soul and therefore would originate in synderesis. Sin, as virtue’s opposite, would then be the contrary originating from the same source.^[62] Philip, however, resolutely maintains the infallibility of synderesis: even if it is understood as the same power of the soul as conscience and desire, it still differs in manner. It helps in producing meritorious actions in the way that inordinate sensuality leads to non-meritorious behavior. If synderesis were to be understood differently, so that it is thought to be flexible toward good and evil, then it could lead to meritorious or non-meritorious deeds. If synderesis is the same as understanding, or understands with a particular habit, then of itself it does not err. It may, however, be clouded by misjudgments and not produce its proper effect on the inferior part of the soul. Error is properly attributed to free choice, when synderesis is obscured. Philip clearly maintains that synderesis in itself always directs one toward good actions.^[63]

In the final discussion concerning the contraries of virtue and vice, Philip places the spiritual gifts and the virtues in both reason and the will. The specific location of the gift of wisdom lies in the superior part of reason, where sin may occur when it seems to lack grace and illumination. When wisdom is said to be in synderesis, it does not follow that error in itself may also lie in synderesis. The soul is deprived of all gifts when it errs through one power. Even if the soul were not to err according to wisdom, it may lose wisdom that is a gift of grace.^[64]

Philip provides medieval moral theory with an infallible source of universal principles. The standard of ethical action is no longer the practically wise person, the phronimos of the Nicomachean Ethics. The habitual potency of synderesis displays a universal code of right and wrong actions. Although medieval thinkers had some difficulty in explaining how the individual comes to develop an innate habit such as synderesis, they agreed upon its central role in the determination of good and evil actions. The moral syllogism described by Aristotle becomes anchored in the soul’s ability to formulate universal precepts, from which the moral agent may deduce particular courses of action. Whether synderesis recognizes the dictates of natural law or the commands of the divine will, the human being has an infallible guide to all ethical decisions.^[65]

The human conscience arises from the conjunction of synderesis with free choice, but it is separate from synderesis itself. Synderesis is unchanging in that it always prescribes the good, but the association with what belongs to reason may allow for the selection of evil. Synderesis, therefore, with the nature of free choice may allow for a proper, or erroneous, exercise of conscience.^[66] Philip asks whether such a power could ever be extinguished. To resolve the question he first distinguishes between the damned and the living. He considers the specific case of heretics and asks whether synderesis alerted them to their evil. While conscience may have directed them to accept martyrdom in defense of their faith, the effect of synderesis was weakened by a lack of true faith. Their error arose not from synderesis, but rather from those actions governed by free choice, or reason. Synderesis is not extinguished in them since evil generally remains displeasing to them, as does their specific failing.^[67] The damned and the devil retain only one element of synderesis, which is the aversion to pain. What they lose is the instinct for goodness and the displeasure arising from the performance of evil.^[68]

Philip determines the meaning of reason in three distinct ways. One manner, which is particularly relevant to moral theory, is the way in which reason belongs to the definition of free choice. So understood, it is called a potency by which one may judge good and evil, and what should be done, or not done. In this way reason is a motivating force to action. Reason may be understood as a power that discerns truth or goodness, not with the aim of action, but merely as a cognitive power. Reason may finally be understood as a power according to which a judgment and desire arise as an end or means to an end. Taken in the first manner, reason is a constituent element of free choice, not so much as comprehension, but as the choice itself; in the second way, it designates a cognitive, but not a moving, force; in the third mode, it implies reason not so much as it does choice. The designation, ‘free’ concerning choice refers to an ability, which belongs to the created free will, to choose between contraries. ‘Reason’ is used for such an operation because it orders actions to an end. There is a two-fold order of reason toward the supreme good: through an examination, and performance, of temporal operations, or through the contemplation and love of eternal objects.^[69] From this order two elements of reason contribute to virtue and vice, but reason itself does not cause sin, but rather error. Despite his claim that reason does not cause sin, Philip places the origin of mortal transgressions in the superior part of reason: “because there exists only in the superior part of reason the power of sinning mortally, and this is because it has an order to contemplating and reflecting upon superior things and should act according to eternal laws.”^[70] Here Philip has implicitly identified the content of synderesis as the eternal laws. Those who do not act according to these precepts have failed to act in the pursuit of goodness and have ignored through their free choice the dictates of synderesis.

The work of Albert the Great marks a significant development in the understanding of ethics in the thirteenth century. The beneficiary of the new translation of the entire text of the NE with the accompanying Greek commentaries, Albert produced two extensive commentaries on the entire text of Aristotle. The first commentary, the Super Ethica, completed shortly before 1250, was the most influential work on Ethics in the Middle Ages.^[71] Before he was able to analyze the entire range of Aristotelian moral questions, Albert addressed topics that reflected the state of moral enquiry in the first half of the century. His first works on ethical topics, the De bono, De natura boni, and the so-called De homine, rely heavily on the partial translation of the NE that was available before the complete translation.

Albert compares intellectual principles to those that govern moral actions, and concludes with Aristotle that while universal principles exist naturally in the intellect they are not the same as moral principles. Since the latter principles are wholly related to human acts, they cannot be actually within the soul naturally. Citing a passage from book two of the NE, Albert concludes that one has an innate ability to begin the process toward virtue but needs habituation to perfect it.^[72] The intellectual principles are complete in the intellect because they are merely to be known through cognition. Even after the moral principles are recognized they must govern actions in order to produce a virtuous habit. To know them only is not sufficient for moral virtue, whereas knowledge alone is the end in the intellectual sphere. The will governs choice in the moral act, and it may direct one to abide by, or ignore, moral principles.

In one of his earliest work on moral philosophy Albert has correctly grasped the mechanism whereby prudence operates: the deduction of a particular action through syllogistic reasoning. What will soon change from Aristotle’s concept of phronesis in the medieval reading of the Ethics is the process of identifying moral principles. Albert indicates in the De bono that prudence takes the principles from law; in his later works he specifies that law to be eternal and divine. Albert considers Aristotle’s claim that prudence is an intellectual process to reflect a general understanding of the way both the practical and speculative intellect comprehend necessary and probable conclusions. For Aristotle to say that comprehension has every truth as its matter does imply that prudence’s primary subject is intellectual truth. Prudence is merely a part of comprehension, and differs from, or is less than, total understanding, which may be considered in three ways: 1) necessary truth ordered to speculation that is the subject and end of science; 2) practical truth ordered to acting by reason of a just and useful good that is the subject of prudence; 3) probable truth in both speculative and practical inquiry that is the subject of opinion.^[73] By means of legal, just and useful reasons prudence chooses whatever it selects, as Paul indicated in I Corinthians: “All things are permitted to me, but not all are helpful; all things are permitted, but not all are constructive.” In Albert’s paraphrase of Paul he emphasizes the legal and useful effects of the actions that prudence commands.^[74]

The act of prudence has different aspects, one of which occurs secundum se, and another which commands movement and action. The act secundum se may be divided further into the antecedent process which is compared to a disposition and potency to virtuous works, and the consequent act which is like a perfection in a ruling element which can bring the action to completion. The antecedent element is further divided: it first regards through reason what is to be done, then it examines what to do through legal, useful and just reasons, subsequently it deliberates how to proceed, and finally commands. The consequent aspect is choice itself: “Such an act whereby it commands action is an opinion about what ought to be done. Prudence and practical reason have the very same acts because reason gives the act and prudence informs it through law, expediency and justice.”^[75] While Aristotle does not have such a complicated process of prudential reasoning, he would not have objected to Albert’s close association of prudence and practical reason with the directive force of reason that considers the importance of law and justice in making practical decisions.

When Albert examines the intellectual virtues treated by Aristotle at the end of the first book of the NE, he notes two important problems with the division of virtues into practical and intellectual. He says that Cicero in De officiis explicitly calls phronesis wisdom (sapientia). If Cicero is indeed correct then phronesis does not differ from sapientia at all. A second problem arises from the translation of Aristotle’s NE. Albert asks why Aristotle does not list prudentia among the intellectual virtues, as he does in the De anima. Since phronesis is left untranslated in the Latin text of the Ethica nova, Albert lists the intellectual virtues as sapientia, intelligentia and phronesis.^[76] In his solution Albert argues first that Aristotle touches upon the general habits of intellectual virtue in the same way, i.e. that reason generally is a potency reflecting all moral elements, or in the way that they are ordered to the concupiscible or irascible part of the soul. In his judgment wisdom in the civic sphere refers only to the habit of morals with an awareness of the final moral cause. Albert clarifies his position by noting that wisdom always aims to designate a type of knowledge that exists through the first cause, but in ethics such wisdom is found in the final cause of happiness and justice. Phronesis in the strict sense taken by Aristotle is called a habit of morals with knowledge of natural and positive law. It also determines right and wrong. As a result phronesis contains a greater cognition of morals than is needed in prudentia. The latter may have knowledge of the the reason ‘because’ (quia) while phronesis and sapientia determine the ‘why’ (propter quid). Phronesis knows the reason why by recognizing what is required and obligated by law; sapientia by recognizing the end itself. Intelligence indicates the same things as prudence which leads to the simple awareness of what to choose for a particular act.^[77] Cicero’s identification of phronesis with wisdom depends upon his broad interpretation of both practical and theoretical wisdom. For Cicero practical wisdom proceeds from divine and human reasons that allow for knowledge of particulars pertaining to action. Cicero then classifies phronesis as a type of wisdom and understanding even if Aristotle did not.^[78]

Unlike Philip the Chancellor, Albert does not introduce the concept of synderesis into his discussion of Aristotle’s doctrine concerning prudence, but does consider it when treating the meaning of natural law. Citing Basil, who placed an awareness of the universal principles of law within a natural ability to judge, and Paul, who claimed the act of law to be written in the heart, Albert accepts the idea that universal legal principles should direct human action. Like William of Auvergne, Albert understands Paul's text to allow for the introduction of the idea of synderesis into the discussion on correct moral laws. In them there can be no error or doubt, since the natural ability to judge is formed by reason and synderesis. So formed, the critical faculty of judgment knows what to do.^[79] Such universal principles are clearly expressed in the decalog, and individual tenets are the belief in one God, to honor one’s parents, not to kill, and the like. These commands are universally taken from natural and written laws (scripta), and are comprehended by that power which responds to reason. Albert compares the process of acting in accordance with natural law to the process whereby the speculative intellect is perfected. The intellect contains a twofold power before it receives an act of knowledge: a potency to know the instruments of knowledge, and the power of knowledge itself. The instruments of knowledge are the first principles of science. The same process holds for the development of a habit of the practical intellect which directs actions. In the knowledge of law the first potency is directed toward its universal principles. Albert argues that before the moral habit can develop there must be knowledge of the terms of the universal imperatives. He says that the knowledge of principles, such as do not steal or commit adultery, is acquired per accidens, that is, through recognition of terms. Because there is no prior understanding, knowledge of such terms is instilled naturally and acquired by subsequent recognition. The writings of Basil and Paul on the topic determine that justice is known by the form of justice impressed upon all those whose life and actions conform to the dictates of the universal commands. In this way one develops a habit of natural law.^[80]

Natural law may be a habit, but not one that in itself is sufficient to produce action. Augustine’s definition of a habit as that by which someone acts as desired refers to a complete habit which has no trace of potency. This type of habit is not one of principles, by whose possession one is led to action. The innate cognition of the imperatives of natural law leads only potentially to corresponding actions which need to be aligned with the dictates of right reason. The potency of the natural habit is actualized when specified by the particulars of human positive law.^[81]

When discussing what this force of nature that law actually is, Albert maintains that it is doubtlessly the light of the agent intellect. This light is a type of intelligible species that leads to an awareness of terms that comprise the first principles of the agent and practical intellects. To assent to such principles of knowledge and actions requires no proof or demonstration.^[82] This natural power is common to both the speculative and practical intellects because the light of the agent intellect is proportional to each by means of the principles, and through these principles one is led to proper conclusions. Albert does not give a definitive response to the question on the source of natural law, but he does say that it arises from reason or even synderesis. In either case it is not its own cause since the agent intellect does not receive any species, or any habit, whether natural or acquired. The natural light may be described as a habit of that which is essentially a form which illustrates and conveys intelligible being through its act, just as the light of the sun is related to all colors in transmitting visible being.^[83] In a strict sense natural law is an innate power as defined by Cicero. The results of this law are the universal moral precepts that the conscience dictates from the very nature of goodness. In a more general sense natural law refers not to human deliberation or reason, but to what is commanded by God according the seeds of law (semina iuris) that are implanted in the human heart. In this way the law, prophecies and the gospels are derived from natural law.^[84]

In another early work, De homine, the literary style and its biographical sketch indicate a product of Albert's teaching activity before the completion of his theological degree. The De homine is part of a larger consideration of all creation and was certainly composed before 1246 and more specifically circa 1242.^[85] This early treatise is very important for the understanding of Albert's views on the mechanism of human moral action, and contains specific discussions devoted to the definition and function of synderesis. While Albert scarcely mentions the concept of synderesis in his other works on moral philosophy, he devotes an entire section to its importance for moral action in the De homine. He takes the claim of Basil that the soul has the natural ability to judge good from evil as his point of departure. This power of the soul naturally has the innate seeds (semina) of judgment from which truth may be cultivated. From Basil’s understanding of synderesis its definition may be expressed as a “virtue of the soul having in itself the fixed and innate seeds of judgment by which we separate evil from good.” Two other conclusions follow from this definition: 1) synderesis is a natural judgment of the soul: 2) it is a potency and not a habit of the soul.^[86] The second conclusion is that of Philip the Chancellor who was instrumental in introducing the notion of synderesis into the discussion on moral action in the thirteenth century, and preferred the designation of synderesis as a habitual potency. Albert does not identify synderesis completely with reason, which does not have the natural judgment, but is rather discursive. Reason also lacks innate seeds of justice and acquires them through custom and the teaching of prudence. Albert does not claim that the principles of synderesis are learned, but rather that reason comes to recognize them through teaching and practice.^[87] Another source for the doctrine of synderesis is Augustine, who wrote that the universals of law were naturally written in the innate ability to make judgments. Since Augustine determined habits to be in the potency or virtue of the soul, synderesis must also be a habit.^[88] Albert identifies Jerome’s Gloss on Ezechiel to be another source for the understanding of synderesis, and cites in his work a passage where Jerome introduces a fourth element into the Platonic division of the soul. In addition to rationality, concupiscence and irascibility the soul possesses synderesis, which is the inextinguishable spark of the conscience. Albert understands Jerome’s Gloss to place synderesis within the genus of the soul’s potencies. As the spark of conscience it cannot exist apart from its corresponding habit. This reading of Jerome is in harmony with the definition given by Basil. Synderesis exists through every mode and apart from any organ, and is superior to reason, desire and irascibility. Finally, it is not a potency mixed with other motivating forces, but rather corrects errors in them.^[89]

Albert’s extensive discussion of the various positions concerning the nature of synderesis summarizes the philosophical-theological deliberations on the topic in the first half of the thirteenth century. In his own determination he accepts the notion that synderesis is a special power of the soul, in which, as Augustine argued, the universal dictates of natural law are displayed. Albert sees a direct connection between the principles of synderesis and those of the speculative sciences. Both have principles and values that human beings do not learn, but are led to truth through their direction. In practice certain universals direct actions through which the practical intellect gains assistance in distinguishing right from wrong in all ethical decisions. As in theory, one does not learn such principles, but, as Jerome says, they are the natural law written on the human spirit. Augustine specifies further the universal commands and gives examples, such as avoid fornication, do not kill, show compassion for the sick, and others. Those commands comprise the subject matter of synderesis and are the immutable principles of moral actions.^[90]

What the Greeks called synderesis Augustine designated as natural ability to judge because human beings have the ability to discern universal principles without deception. The eagle in Ezechiel symbolizes synderesis since it perceives the most elevated ideas which are in harmony with divine justice, but does not apply them to particulars. The application of universal commands to specific acts is the function of reason. The directive force of synderesis is similar to understanding in speculative knowledge, although reason and knowledge govern inferences and conclusions.^[91] Synderesis is a power of the soul, but Basil’s description of it as a potency refers to the seeds of justice and the dictates of natural law that lead to invariable rectitude when cultivated by instruction or justice. Basil called synderesis a potency when the universal principles of law are applied to particular cases through positive law. Positive law may be discovered by reason in particular cases that concern justice.^[92] Jerome’s authority led to Albert’s acceptance of the claim that synderesis is a force of the soul with a habit of the principles of natural law. Jerome called it a spark of conscience because conscience follows from synderesis and reason. While synderesis can never err, reason may sometimes be deceived, a failing which Albert treats in his question on conscience.^[93] When one calls synderesis a habit, one does not mean a simple habit, but rather designates a potency with a habit. A mere habit could never incline one to good, but a potency with a habit could. The combination of potency and habit makes synderesis a true power with the human soul.^[94]

Albert considers synderesis to be a unique power despite its desire for the good about which it makes its judgments. Because of the restrictions to universal judgments, its appetite will not be determined even when it rejects evil, since there can be no motivating force without appetetive desire. This understanding of the psychology of the human action led Aristotle to argue that the intellect moves insofar as it is a certain appetite and by means of appetite. Appetite, however, is not some special power, but rather a general passion for all motivating desires.^[95] Synderesis is not some power united to the other faculties of the soul. Albert thinks that while other powers may be completely, or partially, corrupted, corruption cannot be a principle of actuality. What is the cause of error is the failure of the potency to attain its perfection. Synderesis is a part of the soul, more removed from the corruption of desire than any other of the soul’s components. Its distance from corruption allows it to remain unconquered, although some may claim it to be part of the primary rectitude in all the powers of the soul.^[96] Philosophers ignored synderesis because they distinguished potencies according to general objects. When they considered actions they did so from the perspective of human law. Christian thinkers, however, made more specific classifications and added the universal principles of divine law to that of human justice. As a result, they applied synderesis to principles and the superior part of reason. Synderesis allows for contemplation of divine justice in accordance with eternal standards. The philosophers did not posit any such eternal ideals.^[97]

Theological arguments dominate the question whether synderesis is able to err or sin. If one is condemned to eternal damnation then every human element must thereby be punished. The logical conclusion would be that every potency has sinned. If a human being is wholly corrupted by sin, then synderesis must also bear the stains of error. Like Philip the Chancellor, Albert wonders whether heretics and pagans, who persist in error, are examples of those whose synderesis has become corrupted. Basil, however, wrote that the mind’s natural judgment always accepts what is praiseworthy and rejects evil. Such a power can never consent to sin. John Chrysostom speaks of the incorruptible judgment of conscience, which Albert takes to mean the spark of synderesis.^[98] Albert agrees with Basil and John Chrysostom that synderesis never errs because it involves only innate universal principles. Reason is the source of error when it applies universals to particular decision, and errs because it is a lower faculty than synderesis. The Christian authors do not elevate reason to the same level as the Greek philosophers did.^[99] Even the condemantion and damnation of the whole person because of sin does not destroy the power to reject evil. In heretics and unbelievers error originates not in synderesis, but rather in reason’s application. Synderesis commands only that faith requires defending, or that faith and justice should inform a life. The particular applications concerning what constitutes faith and justice come from reason which may lead to error.^[100]

Conscience is the final element in the moral process that results from the practical syllogism. Albert defines conscience generally as the conclusion of practical reason which follows from the general premise of synderesis and the minor premise of reason. O. Lottin considers Albert's treatment of synderesis and conscience to be similar to a modern theory of the norm of morality.^[101] When someone asks why the conscience dictates something is to be done, the response is because that something is good. If one persists and asks for what reason is something good to be done, the answer is that every good should be performed. These simple questions form the following syllogism: Every good is to be done; this is good; it, therefore, should be done. The major premise depends upon synderesis whose task is to direct one to good through universal principles (rationes). The minor comes from reason which aligns the particular with the universal. The conclusion to act arises from conscience which recognizes the connection between the two premises.^[102] The practical syllogism approximates the process of theoretical reasoning, since the principles of synderesis provide premises known per se. The premise that should be evident through reason often is overlooked because experience is lacking. As a result, error creeps into the particular conclusion.^[103] Synderesis, rather than reason, is called the spark of conscience because the former provides immutable rectitude, while the latter may fall into the darkness of error.^[104] While conscience may at times cause moral error, Albert often indicates that the more common source of moral evil lies in a false conclusion of reason. Conscience may sometimes err when both the dictates of synderesis and the direction of reason may not coincide.^[105] Albert stresses the importance “of introducing into the practical syllogism an infallible source of the major premises capable always of envisioning the sovereign good; towards this end it directs action. Such is the role of synderesis.”^[106]

In a series of questions composed about 1250 Albert again raises the question of the meaning of synderesis, first in an article on the powers of reason. The writings of Augustine provide the inspiration for Albert's findings. The nature of justice and other virtues, he argues, may be considered universally according to the universal principles of right. In this way there can be no error because of the power of synderesis. Even a heretic recognizes the universal principle that one should believe what is necessary to believe, but is deceived in believing a particular doctrine.^[107] The content of synderesis is contained in the universal principles of law which are written in the natural ability to judge. This natural ability is the true meaning of synderesis, which Albert believes Augustine determined.^[108] Albert responds to the question whether synderesis is a potency or habit initially with the simple statement that it is a rational potency. But this answer demands more explanation. Synderesis is a moving power in that it directs one to a proper end, either actually or potentially, but it is also a directive power because it involves universal principles, which function similarly to those in intellectual knowledge. Just as the recognition of intellectual principles guides one to knowledge, the apprehension of moral imperatives leads to correct action.^[109]

For a modern interpreter of Albert the association of the habit with the potency preserves the infallibility of synderesis, and the perfection that comes primarily from the habit determines the potency to the individual act.^[110] C. Trottmann here clearly recognizes the dilemma that introduction of synderesis into the understanding of Aristotelian ethics presents. If one knows infallibily the principles of right action then human moral choice must always be determined to what is right. But the potency lies dormant until it is perfected by the natural habit which pursues the correct paths of action. Synderesis is neither an ordinary potency nor an ordinary habit because each requires the presence of the other in order to function properly. The seemingly complex theory concerning the meaning of synderesis is Albert's attempt to preserve the innate rectitude of the cognitive function as well as the freedom of the appetitive one. He, like his medieval contemporaries, provides primarily a basis for universal codes of conduct even with their endeavors to preserve voluntary liberty.

In itself, synderesis can never err, but despite its rule over other powers, moral error can occur. Albert compares such error to a soldier who may fall from his horse through no fault of his own, but because the horse missteps. The fall from rectitude is ascribed to synderesis only with respect to the effect, just as the horseman's fall is produced by his mount.^[111] Albert distinguishes synderesis as a rational potency 'as nature' from a rational potency 'as reason'. ‘As nature’ it is understood as that which provides for a human being those things which preserve human nature. Such a concept of nature prevents synderesis from being turned from its purpose because it is perfected in those principles imparted by its very creation. It should not be thought to act 'as nature' in the sense that the potency is determined to one effect only, as the nature of heavy bodies always fall downward.^[112]

Albert does not discuss synderesis specifically in his later moral works, but he does consider the topic of natural law and its importance for ethical decisions. The commentary on the complete text of the NE, known as the Super Ethica, is an important contribution to the history of moral philosophy, and contains an analysis of the principles of moral actions. Albert was the first medieval author to benefit from the translation of the entire text of Aristotle and the accompanying Greek commentaries. The work, which reflects Albert’s teaching at Cologne, includes questions and commentaries on every topic in Aristotle’s text. Thomas Aquinas attended the lectures on the Ethics at the Dominican House of Studies, and benefitted greatly from Albert's careful exposition of Aristotle's text.^[113] Modern scholars, such as G. Wieland and L. Sturlese regard this work as a comprehensive foundation of a philosophy independent of theology and based entirely on reason entirely free of the religious domination of the age.^[114] Other scholars deny so radical a departure from theological doctrines in Albert's first commentary on the NE,^[115] but in either case this commentary had an enormous influence on subsequent discussions on topics concerning human goodness, happiness and moral virtue in the Middle Ages.

All law and all just acts have fairness and legitimacy either from their substance or nature, which is natural law, or they derive their virtue from custom, which is legal justice. The former type of justice prohibits actions, whereas the latter understands them to be evil.^[116] Natural justice arises from its connection with human nature as characterized by reason. Reason is the principle of human actions insofar as they are human.^[117] Albert understands the ideal of natural justice in two ways, the first of which he claims is found in Plato’s Timaeus. Justice exists in natural things, as a type of rectitude that aligns such things with an exemplar. Such a doctrine belongs either to metaphysical or natural science. Another kind of natural justice arises from an innate principle of human nature. The latter type of justice is moral in subject and pertains thereby to the science of ethics.^[118] Natural law itself may be understood according to a naturally innate habit, and is therefore not acquired. In this way the principles of natural law are similar to the first premisses of speculative sciences. Examples of what may be innately known are commands, such as do not harm others, or respect one’s parents. The principles direct moral actions as they are applied to specific circumstances.^[119]

Natural justice has vigor and equity from its very substance, traits that are in themselves consistent with reason and effective in attaining human goodness. This type of justice is applied in particular cases through custom and acceptance of law. Albert understands both of Cicero’s descriptions of natural law to be included within Aristotle’s understanding of the concept of natural law. Both the claim that the beginning of law comes from nature and that certain things come into use by reason of utility fall under Aristotle’s description of natural law. A third type of law is enacted by a wise person in order to direct human behavior.^[120] The principles of natural law can never vary essentially, but their use may differ when they are applied to particular cases.^[121]

The judgment that occurs within the prudential act is not the same as the virtue itself, but is the inducement to action. This incitement to action is expressed in a command, expressed as a major proposition, such as do not fornicate, or in the minor premise and the particular circumstances, such as to lie with this person is fornication. The final element in prudential reasoning is the conclusion, which is to know in acting that something should, or should not, be done. Intemperate delight does not destroy the habit of prudence, but it does corrupt its command. Immoderate pleasure does not affect the major proposition, but partly corrupts the minor, and destroys completely the conclusive command when it blinds reason.^[122] Aristotle’s choice of Pericles as the phronimos reinforces Albert’s belief that prudence functions only in the practical areas of human life. Pericles was accomplished in civic decisions that governed his household and his city.^[123]

Prudence cannot be simply and totally forgotten, although the prudent person may be less able to apply its principles to a particular act, if distracted by passion. Albert argues against the possibility of forgetting the virtue, since the universal innate principles of law are always present. In these principles prudence subtantially exists. Because the principles must be applied to particular acts, a flexible rule that time and experience construct guides a prudent person.^[124] Prudence must always include knowledge of both universals and particulars. Since it aims at an action that consists in a particular choice, it requires universal, particular and active knowledge. Albert considers the nature of prudence to be more active, since it may produce correct particular actions without true knowledge of universals, especially in the early stages of its development when one imitates the good actions of wise persons.^[125] Any action requires knowledge of the universal principle and its application to a particular choice, since no act can occur except particularly.^[126] Since prudence applies the universal principle to a particular choice, Albert says that it is midway (media) between the moral and intellectual virtues, and cannot be a purely intellectual process.^[127] Reason perfected to its best state consists in knowledge of universals, but perfection in its directive capacity comes from particular awareness, which produces what Albert calls the inferior virtues. Prudence perfected in the second manner is the guide to all moral virtues.^[128]

Prudence and politics are in actuality the same habit with respect to their subject, but differ in their manner or nature. Prudence is associated with the governing aspect of reason, but politics is more concerned with the act. Politics is related to prudence as that which follows from the governing principle.^[129] Albert does not claim that everyone acts from knowledge of infallible principles, since one could operate from the false premise that an act of adultery is an expression of voluntary freedom. In such a case freedom is understood as a good, but the identification of adultery and freedom is erroneous. As a result, a stated rule may be false, although the good person would recognize true principles and reject false ones.^[130]

Albert again recognizes a type of circularity in Aristotle’s formulation of the practical syllogism. Unlike the order of speculative science, practical reasoning arises from the particular which is desired and intended in action. The particular is the foundation for the subsequent elements in the syllogism. The order in the practical syllogism is the reason why Aristotle says that the motion of the appetite is circular. The appetitive power is passive and cannot be perfected except by the species of the object acting upon it. Desire provoked by the appearance of the desirable object moves the power in the muscles and nerves. These physical movements lead to the attainment of the object, and so the process ends with that which began the process.^[131] The particular object of desire is the motivating principle in action despite its placement in the practical syllogism as the minor premise, which states this object is desirable. Its motivating force makes it more effective in producing action than the first principles, but also allows for greater uncertainty in practical reasoning.^[132] Actions that comprise a good life are naturally innate in the manner of a planting bed (seminaria) of law. Experiences through which common principles are determined present themselves to all since they live in accordance with the human way of existence. These innate abilities need nurturing through time and by experience and as they mature they end the fluidity of youth.^[133]

In 1262 Albert composed a second commentary on the Nicomachean Ethics which has come to be known as the Paraphrase. The name often leads to a dismissal of the work as inferior to, and less important than, the Super Ethica, but J. Müller has argued that the later work can only help to enrich our understanding of Albert’s positions on the nature and breadth of ethical science.^[134] In this work Albert does not mention specifically the concept of synderesis, but it lies behind his assertion that all human beings have the ability to attain moral perfection because they have, as Boethius stated, the innate seeds of virtue that they can develop.^[135] The primary good in a moral genus, and the source of all other subordinate goods, is the voluntary act which is determined to the proper subject (ad propriam materiam) by reason. Albert specifies these goods as feeding the hungry and assisting the poor. Such actions, which have the first potency to goodness, are also the primary subjects of goodness, even if they may be conditioned by circumstances.^[136] Reason analyzes all the factors that contribute to the attainment of the desired goal. One may view reason in its quest for truth or in its ability to lead to just actions. In the first way, a human being is perfected according to the mode of humanity which is superior to the moral ability to overcome the inclination of passions. Again Albert maintains the hierarchy of human goals and makes the purely intellectual life the supreme achievement of the soul.^[137]

The human soul does not naturally produce virtue, but does have a susceptibility to virtue by way of inception, or, as Albert says, through the mode of a certain seed. The instruments by which the seed grows are within the soul, as is clear in the case of intellectual excellence whose first seeds are the intellectual lights proceeding from the first intellectuality (ab intellectualitate prima). The instruments are the first principles that are the common conceptions of the intellect. As Boethius says, any hearing of the first principles demonstrates their validity. If they were not within the soul no one could become wise or know through any study whatsoever.^[138] The same process also directs the moral virtues. To produce virtue from the natural seeds within the soul five qualities must characterize virtuous operations: 1) they must be done in accordance with right reason; 2) what is needed to produce goodness is present; 3) the operation is directed to a mean; 4) the operation produces and sustains virtue; 5) the operation always produces either pleasure or pain in the moral agent. With these five conditions the natural ability to become virtuous actualizes itself into the necessary corresponding habits.^[139]

Moral error may be the result of ignorance since one can be unaware of the meaning of either the major or minor proposition. Ignorance of the practical syllogism differs from that of the contemplative, since in the pratical syllogism the major premise, if known, determines action, and the minor comes from the elective appetite leading to the impulse to act. The conclusion is the choice of the better alternative. There is no error from the major premise which contains the universal principles directing action. These principles may come from natural or positive law, or may be determined by the rule of reason in the absence of any authority. Elective desire features both choice and appetite. Evil results from the error and ignorance that appetite may produce. Appetite unrestrained by reason produces evil, but choice has dominion over desire and may produce good in accordance with the principles known through reason.^[140] When Aristotle claimed that there can be no deliberation about the ends of actions Albert understands him to refer to certain and self-sufficient principles.^[141] Although Aristotle does not expressly identify the ends of moral action that require no deliberation, Albert’s identification of the ends and principles is not entirely wrong. Albert will, however, go further than Aristotle when he specifies in book V of his commentary such first propositions to be the dictates of natural and divine law.

The will is simply the appetite of the rational soul and is directed to the end only.^[142] The pivotal virtues of the soul are called 'cardinal' because they are the ones around which an entire human life revolves. Prudence has the principal place among all moral virtues in ordering the passions and determining the mean. Prudence is materially a moral virtue in its consideration of practice, but formally it belongs to intellectual virtues because of its recognition of universal principles.^[143] Simple natural justice has no measure of legal justice since its principles are universally assumed and accepted, and has a universal power to obligate. For this reason, Cicero claimed justice to arise from nature, since opinion does not generate it, but rather it is innate in all. This justice may be generally considered in itself or determined sub specie. If understood in itself, justice functions according to reason, but obligates through a natural instinct, and not by the application of justice. In this way one speaks of the natural justice of the union of male and female, procreation, repelling force and the preservation of life.^[144] Specific natural justice (sub specie) is that by which reason informed by rational principles alone formulates commands. Such principles are not discovered by enquiry or discussion. Cicero speaks of natural obligations of this kind and lists them as religion, piety, grace, and truth, among others.^[145]

Natural law requires veneration of God, and despite civic laws demanding religious observance, political justice is not the same as natural justice. The preservation of the city may be an example of natural justice, since it conforms to the demands of reason, but specific laws are not natural. Likewise, the command to honor one’s parents is an individual precept of natural justice, but the manner of its performance is not, just as particular ways of worship are not prescribed by nature.^[146] Truly natural principles are immediatley apprehended and do not emerge from study and discussion which produce the dictates of habitual justice.^[147] The principles of natural justice are so compelling they demand immediate acceptance, while their negations must be rejected. Reason tells all to venerate the divine beings, to honor parents, to socialize with equals and to respect superiors. Albert extends the list of natural precepts to include the recognition of one God, the prohibition against perjury and bearing false witness and the bans against adultery, theft and murder.^[148]

Since human decisions end in particular actions the prudent person must know both universal principles and particular conclusions drawn from them. True prudential reason goes beyond the universal maxims of practical knowledge and results in a type of expertise comparable to medical skill. A good doctor knows both universal scientific theorems and their particular applications, since the former are ineffective without the latter. Both are present in the prudent person who uses the universal rule to govern the particular application. The universals are always theoretical and architectonic; the individual conclusions are always useful and practical.^[149] Only experience can provide knowledge sufficient enough to align particular choices with the dictates of universal principles.^[150]

Thomas Aquinas devotes six questions to the topic of prudence in the Secunda secundae of the Summa theologiae, and begins with a consideration of three well-known definitions. The first two are taken from Augustine and the third comes from Aristotle. Thomas cites Augustine’s designations of prudence as love (amor) and knowledge (cognitio) as well as Aristotle’s description of prudence’s function in art as the deliberate choice of error. He later adds Isadore of Seville’s depiction of prudence as a type of foresight (porro videns), which demonstrates that prudence pertains to the cognitive powers of the soul. Prudence’s vision allows one to predict future events from past and present experiences.^[151] Thomas interprets Augustine’s description of prudence as love in terms of how the will moves potencies to act. Since the first act of appetitive virtue is love, prudence may be called love insofar as love moves one to action. Augustine refined his definition by adding the element of discernment that helps one to makes correct choices that lead to God.^[152] Prudence pertains most properly to deliberation, but since all choice involves deliberative judgment, prudence may be also attributed to the art of choosing.^[153]

Thomas understands Aristotle's opening line on the topic of prudence, “it is characteristic of the practically wise person to be able to deliberate well,” to pertain to the ability to exercise right reason over choices that lead to desired ends. Such ability is the mark of practical reason.^[154] In any area the wise person considers the absolute highest cause. In human actions the supreme cause is the universal end for every life. It is this goal to which prudence directs actions, since the one who reasons well about a completely good life (totum bene vivere) is absolutely prudent and wise in human affairs. Thomas' choice of the phrase, bene vivere, demonstrates his intention to limit prudence to the practical world of human interactions, whose mastery makes one humanly wise, but does not give result in unqualified wisdom.^[155]

Thomas accepts Aristotle's depiction of prudence's ability to know both universal principles and individual applications. For Thomas both the consideration of reason and its application to an act leading to an end are features of prudence. No one can apply one thing to another unless a person knows both applications. Because operations consist in individual choices the prudens knows both the universal principles of reason and the individual operations that result from them.^[156] The combination of the right consideration of reason and the rectitude of the appetite required of prudence places it among both the intellectual and moral virtues.^[157] Prudence, however, is distinguished from other intellectual virtues by the material diversity of the objects, since wisdom, knowledge and understanding consider necessity. Prudence's objects are actions within the moral agent and allows for variations according to circumstances and abilities. Prudence differs from moral virtues according to a formally distinct nature of the powers of the intellect and the appetite. Prudence takes a special place in the list of human virtues because of its affinity for both kinds of virtue.^[158]

Truth for the practical intellect differs from that of the speculative intellect since the latter kind of truth consists in the conformity of the intellect to the object of knowledge. Because the intellect cannot conform infallibly to the object in contingent judgments no necessary intellectual habit of contingent events can be developed. The truth for the practical intellect consists in its conformity to correct appetite. This conformity does not admit necessity, for then the will could not be free. Conformity to right appetite occurs internally concerning contingent actions (prudence), or in the production of some external object (art).^[159] Prudence has a connection to both the speculative and practical powers within the intellect. In actions three rational operations, which are deliberation, judgment and command, act together. The first two acts are functions of the intellect, but command leads to action, and, as such, belongs properly to the practical intellect. It is the principle of action to which all others in the process are ordered. In prudence, whose primary act is to command, the action of the practical intellect directs the deliberative processes of the speculative intellect.^[160] Thomas calls prudence an intellectual virtue according to its essence, but it belongs to the moral virtues according to its subject, since it is right reason in actions.^[161] Prudence is needed for all moral virtues because it determines the proper means to the desired end and issues appropriate commands. Despite its classification as an intellectual virtue it functions in the moral realm. It does, however, comprehend the naturally known moral principles and deduces correct actions from them.^[162]

While other intellectual virtues may exist without moral virtue prudence cannot, because it requires right reason in both universal and particular judgments. Right reason presupposes a comprehension of principles from which particular actions may be deduced. These principles are known by a natural understanding whereby one knows that no evil should be performed. Although these principles direct action, they do not translate immediately into action, since passion may corrupt their commands. Just as the disposition to act rightly concerning principles comes from natural understanding or the habit of knowledge, so too do habits concerning natural judgments concerning ends arise from moral virtue. Natural virtue displays the proper end in particular choices in accordance with the natural knowledge of universal imperatives.^[163]

Virtue has a natural component since human rationality knows naturally innate principles of science and action. Like Albert, Thomas designates these principles as a type of fertile ground (seminaria) for intellectual and moral virtues. The will also has a natural desire for goodness in harmony with reason. Individual material differences explain why certain people seem to have a disposition toward developing virtues more completely than others.^[164] Specific measures determine goodness and because there are two ends for human existence there must be two distinct measures: divine law and human reason. Because the former is superior to the latter it extends further and rules all human actions. Human virtue ordered to the good regulated by reason can have its origin in human acts as they proceed from reason itself. Virtue ordered to the good regulated by divine law cannot originate in human operations whose principle is reason, but are caused only by a divine operation.^[165] Thomas has the opportunity here to accept the Ciceronian unification of Platonic and Aristotelian ethics, whereby the eternal law is subject to the interpretations of the wise person, but he chooses to keep the two moral ends separate because reason can never unite the two.

No moral virtue can exist without prudence, just as prudence cannot exist without moral virtues, since the virtues direct one properly to the ends by which the nature of prudence proceeds. For the true nature of prudence there is a greater requirement for the proper relation to the final end, which is made by charity, than to other ends that are made by moral virtue. The relation of charity to the final end is similar to right reason in speculative sciences that need the prime indemonstrable principle of non–contradiction. What Thomas calls infused prudence cannot exist without charity as can no other virtue which orders a human being to the ultimate end.^[166]

Thomas views the question concerning the supremacy of the virtue of wisdom with respect to its relation to prudence. He notes in his preliminary arguments that since prudence directs human action to happiness it seems to rule over wisdom. In his response Thomas understands the specific character of any virtue in relation to its object. Since wisdom’s object is the supreme cause of all things, God, it must take the preeminent position among all virtues. Wisdom can make valid judgments concerning all other intellectual virtues and therefore orders all theoretical pursuits in an architectonic hierarchy.^[167] Because prudence is limited to human affairs it cannot be superior to the wisdom that considers the highest cause. Thomas unites Aristotle’s claims that man is supreme on earth with Paul’s assertion that “what is spiritual judges all things and is judged by no one.” According to Thomas prudence is not involved in the objects of wisdom, although it may govern actions that lead to it. Prudence ministers to wisdom in preparing the way just as a courtier serves a king.^[168]

In the discussion on prudence Thomas refers obliquely to the concepts of synderesis and natural law. He argues that because the good for the soul exists according to reason the ends of moral virtue necessarily preexist in reason. The method of understanding ends is similar to the immediate apprehension of scientific axioms. The moral principles naturally known are the ends of the moral virtues, but they differ from scientific laws in that they lead to action.^[169] Thomas makes the implied reference explicit when he claims that “natural reason, which is called synderesis, displays the end in moral virtues”^[170] and thereby moves prudence itself.^[171] For Aristotle virtue displays the end in moral decisions, but Thomas makes the process less flexible when he makes synderesis the moving force of reason. Like his medieval predecessors, who sought to place the principles of moral practice on a foundation more secure than the choices of a good person, Thomas chooses to introduce a measure of ethical certitude in the innate habit of synderesis. In his early work, the commentary on Peter Lombard's Sentences Thomas considers the state of human beings before Adam's fall from grace, and then discusses the human natural power to avoid sin. In these questions the concept of synderesis has an important role in directing human beings to choose what is good. After a treatment of the problem of free choice Thomas abruptly introduces the question whether synderesis is a habit or a potency. In the preliminary arguments he notes that a habit can only be attributed to a potency, but Augustine says that the universal precepts of law are written in the natural judgment which is synderesis. Since there is a habit of the universal precepts of law synderesis may seem to be a potency to which the habit is attributed. Thomas' adroit answer to the question is less important here than his unqualified acceptance of Augustine's assertion that the precepts of law are collected in an innate habit. They form the unshakeable foundation for proper moral choices.^[172]

In the commentary on the Sentences one finds a position that directs many subsequent conclusions throughout Thomas' career: the notion that order and reason are derived from a single principle. Thomas compares the process of reasoning in practical science to that of theoretical sciences:

Just as in the motion of natural things all motion proceed from an unmoved mover... every dissimilar relation comes from one relation that is similar in some way, so too does the process of reason function. Since reason has a certain variety and is mobile in some way insofar as it deduces conclusions from principles, in the process it is frequently deceived, all reason must proceed from some cognition by which it has a certain uniformity and stasis. This does not occur by a discursive investigation, but is offered immediately to the understanding, just as reason in speculative <sciences> is deduced from some principles known in themselves whose habit is called understanding.^[173]

The principles of action are known immediately and include the command to avoid evil and obey the laws of God. The resulting habit is synderesis, which differs from practical reason, not by the substance of the potency, but because it is an innate habit. Synderesis is somehow innate because of the very light of the agent intellect, just as this light provides immediate comprehension of statements, such as the whole is greater than any part. In the commentary on the Sentences, as in the later works, Thomas does not seem to concern himself greatly with a precise designation of synderesis: "And so I say that synderesis designates a habit alone or a potency subject to an innate habit in us."^[174] This natural habit can never be lost, as is evident from the habit of recognizing principles of speculative sciences that a human being always retains.

Later in the commentary Thomas again appeals to the argument from order as a basis from his theory about synderesis. Divine wisdom, as Dionysius claimed, unites the first elements of lower things to the last elements of higher ones, and in the order of creation what follows must be similar to what precedes. Their similarity is the result of participation in perfection, and so an inferior creature participates by means of its similitude to the superior one. In the order of creatures the angelic nature is first and is followed by those with a rational soul. But the soul is united to a body, and its knowledge then arises from sensation which leads by inquisition to understanding. Angelic incorporeal beings require no inquisitive process to apprehend truth because angelic nature is purely intellectual, while the embodied soul is properly called rational. Because the rational soul is close to the angelic nature it can participate in intellectual virtue and apprehend certain truths without discursive reason. Such truths include the first principles of speculative and practical sciences. In practical inquiry the immediate apprehension of first principles is the habit of synderesis. Thomas refers to this ability as a spark since just as a spark is a small bit flying out from the fire, so too is this power (virtus) a certain modest participation in the intellectuality that characterizes angelic beings. This spark is the supreme element in rational natures, which is why Jerome depicted it as an eagle soaring above all other creatures. It is synderesis, which cannot be extinguished and always repels anything which contravenes natural principles.^[175]

The most extensive treatment of the topic of synderesis appears in the disputed questions on truth (De veritate 16, articles 1, 2 and 3). Thomas begins with the usual question whether synderesis is to be considered a potency or a habit. In the preliminary arguments two important comments on synderesis emerge: 1) the universal principles of law are said to be attributed to synderesis; 2) in the natural ability to judge (synderesis) there are certain true immutable rules and the 'lights' of virtue.^[176] However Thomas may resolve the question of the nature of synderesis, he maintains these features of synderesis throughout his discussions. The resolution to the question includes a cursory summary of contemporary opinions, including that of Albert. In his own response Thomas again connects human rationality with the angelic nature. Human beings can recognize those truths that produce all subsequent knowledge without discursive investigation in both the speculative and practical areas.^[177] Thomas again uses Albert's term in claiming that such innate knowledge is similar to fertile ground (seminarium) for subsequent conclusions, just as natural seeds must exist before subsequent vegetation. This type of knowledge must be habitual so that it will be ready for use when needed. As in the theoretical sciences the first principles direct all subsequent conclusions, so too in moral reasoning a certain natural habit of the first principles of action must exist as the universal principles of natural law. This habit, says Thomas, pertains to synderesis and exists in no other potency than reason.^[178] Lottin claims that the definitions of natural law and synderesis may be made more precise by referring to the former as that which is formally constituted by the first principles of the moral order, while the latter may be considered as the innate disposition which expresses them.^[179]

Thomas again refrains from determining precisely the nature of synderesis, since he says “this term, synderesis, either designates absolutely a natural habit similar to the habit of principles, or designates the very power of reason with such a habit, and whichever of these makes little difference because it produces doubt only concerning the meaning of the term.”^[180] Synderesis refers generally to what Thomas calls both superior and inferior reason. The habit of universal legal principles contains certain precepts that reflect eternal commands, such as obedience to God. It also indicates lower precepts, such as living in accord with reason. Synderesis refers to immutable commands that can never change, but it also has relevance to mutable beings that are bound by the necessity of truth. Just as the whole will always be greater than any part even though the whole may change, so too must mutable human beings live always according to reason. Synderesis, therefore, implies both objective and subjective necessity.^[181] Without eternal principles a human being could never overcome moral uncertainty and chaos, since nature always intends what is good. In all natural acts the eternal immutable principles preserve moral rectitude. Aristotle's assertion that principles must endure is the foundation for stability and certitude in all endeavors.^[182] The first principles can never admit error, for then all subsequent information could be doubted. To ensure moral rectitude the permanent principle against which all acts are measured is synderesis, whose task is to resist all evil and assent to all good. All subsequent moral conclusions follow from this command.^[183]

Thomas again compares synderesis to the light of the active intellect when he responds to the question whether synderesis may be extinguished. With reference to the habitual light of synderesis it can never be lost, just as the human soul may never be deprived of the light of the agent intellect. This light arises from the intellectual nature of the soul that always displays the good. Synderesis may be thought to be lost only by some organic impediment that interferes with the intellectual ability, or in the particular choice which strays from the universal principle.^[184] In the Summa theologiae Thomas is more emphatic in his designation of the synderesis as a habit: “synderesis is not a potency but a habit, although some say synderesis is a certain potency higher than reason; some say it is reason itself, not as it is reason, but as nature.”^[185] Just as there is no special potency to know theoretical principles, but only a particular habit of understanding, so too is there no special potency to comprehend practical principles, but rather only the particular natural habit of synderesis.^[186] True and perfect prudence requires correct deliberation, judgment and command about what leads to a good end for an entire life. Such prudence cannot be found in sinners, because, as Aristotle said, it is not possible to be prudent and not to be good. One may say that an evildoer has a type of prudential similitude as he organizes his actions to attain a corrupt end. One may speak of a ‘good’ thief, but only in the sense that the thief successfully executes his crime. He cannot be designated as good in a moral or human sense.^[187]

Synderesis always proposes the proper principles of action to the intellect just as the mind immediately intuits the major premises in scientific demonstrations, but the pursuit of pleasure may corrupt the judgment of reason. As a result, the true end of action may be obscured and the estimation of the true end may be lost through desire.^[188] Moral virtue ensures the rectitude of judgment concerning prudential principles that appear to the intellect as ends of action. Thomas argues that moral virtue in its role of preserving principles has a type of necessity, which is the deduction of correct individual acts when reason functions properly.^[189] In its subject matter prudence does not follow necessarily because it requires the rectitude of the appetite. Since practical decisions require alternatives, prudence is placed most properly in the 'ratiocinative' or 'opinionative' part of the soul.^[190]

The prudential process can admit error in two ways: failure to recognize the universal, as one might not recognize the principle that heavy water is bad; or an inability to apply or recognize a particular instance, such as this water is stagnant.^[191] The principles are not subject to a rational process, but rather to one of understanding (intellectus), which immediately grasps the universal premises of the moral syllogism. Prudence also must understand the final premise in action that necessarily leads to activity. Prudence does not achieve the same level of certainty as science since its final term is not proved by reason, but rather an interior perception by which one apprehends images (imaginabilia) in the manner of a mathematician recognizing a triangle.^[192] Thomas differentiates the type of understanding (intellectus) in practical decisions from that involved in theoretical comprehension. Practical understanding must grasp the significance of singular and contingent elements that are not immediately apparent. Singular apprehensions lead to the formulation of universals, for example, certain herbs are conducive to health. Sense experience must be operative in both the construction of the major premise as well as in the conclusion of the practical syllogism. The internal awareness that certain herbs produce health may be a universal, but is not useful until one recognizes that particular plants belong to the category of producing health. Both types of understanding are needed in order for the syllogism to function properly.^[193]

The two principal virtues leading to happiness are wisdom and prudence, and both Aristotle and Thomas perceived a need to demonstrate how they contribute to the good life.^[194] Thomas views the relation of the two virtues in much the same way as his teacher, Albert. In comparison to wisdom prudence is inferior in dignity even though it may seem superior because of its ability to command action. At this point in his commentary on the NE Thomas might have departed from Albert’s interpretation and provided a theory closer to a unified notion of happiness, but he quickly returns to a hierarchical ordering of virtues. Thomas argues that the possible superiority of prudence is offered only in the manner of a question (per modum dubitationis).^[195] The usefulness of the two primary virtues lies in their capacity to perfect the rational parts of the soul. Even if they were to contribute nothing to happiness, they would be desirable as perfections, but they, of course, do comprise a great part of happiness. Happiness is in fact the perfection of the soul, and prudence and wisdom, therefore, must be elements of human moral goodness. One who possesses both wisdom and prudence, and who acts in accordance with their habits, must be happy. Thomas says this conclusion is especially true for wisdom, “because in its operations consists a more powerful happiness (potior felicitas).^[196]

Like Albert, Thomas identifies prudence's function to be the selection of the appropriate means to ends to which moral virtue directs the appetite. In the virtuous act moral virtue perfects the appetite and participates in reason, while prudence contributes by perfecting reason.^[197] Thomas detects an element of circularity in the Aristotelian doctrine since there can be no prudence without moral virtue and no moral virtue without prudence. Both are needed since moral virtues require an operative principle that constructs ways that lead to the end. This principle is called 'dinotic' and is like a certain ingenuity or industry that permits the realization of the intention. Prudence contributes to the dinotic potency by directing one always to moral goodness, although ingenuity and industry may be directed to evil goals.^[198] Thomas avoids a more difficult question concerning the relation of moral virtue and prudence. If one needs moral virtue to be prudent and prudence leads to moral virtue, it is difficult to explain how either may be generated. One must ask how moral virtue may display the end to one who is not already virtuous. If one has moral virtue then prudence would not be developed, but comes simultaneously with the perception of the moral ends. Certainly this understanding of virtue neither Aristotle nor his medieval commentators accepted and the difficulty may have led the medieval authors to introduce the idea of synderesis as the innate ability to recognize the proper principles of action. Once they are known, then the experience required in the development of prudence may proceed according to a correct path. With the goals recognized, the good person develops practical wisdom through a variety of experiences concerning the best means to the appropriate ends. Thomas sees some indication of this type of reasoning in Aristotle's claim that a natural disposition to virtue seems to exist in some persons. Unlike Aristotle, who identified some as naturally prone to specific virtues, such as courage and generosity, Thomas argues that natural dispositions come from both reason and the will. Human reason naturally recognizes first principles of action, such as one ought not to harm another. The will has a natural inclination to virtue in that it is moved by a good perceived as its appropriate object. The sensitive intellects of composite human beings differ according to individuals, and are the reason why certain people are prone to specific virtues and vices. Since the will and reason are common to all the first two dispositions to virtue are universal.^[199]

Although prudence is an intellectual virtue it is joined to moral virtue through a certain affinity since the principles of prudence are received through moral virtues whose end are prudence's principles. Prudence conveys the rectitude of moral virtues since it makes the choice concerning the means to an end right. Since moral virtue and prudence control the emotions that arise from the composite being they both concern the union of body and soul, rather than the intellect alone.^[200]

In his discussions on synderesis and prudence Thomas does not specify the commands that originate in the habit of synderesis, but his identification of the dictates of natural law and the principles of synderesis provide explicit direction in prudential decisions. While very little guidance arises from the admonition to do good and avoid evil, Thomas constructs a hierarchy of duties within the natural law.^[201] Thomas makes the close connection between synderesis and natural law clear in the Summa theologiae: “synderesis is called the law of our intellect insofar as it is a habit containing the precepts of natural law, which are the first principles of human acts.”^[202] Thomas asks whether natural law contains different formulations or only one general principle. In his answer Thomas compares the principles of natural law to those of any demonstrative science. In each there are a number of principles that are known in themselves. Principles are known in themselves in two ways: 1) according to themselves (secundum se) and 2) according to the state of the knower. Thomas does not really distinguish the principles objectively, but rather according to the state of the subject:

[…] something is said to be known in itself in two ways, in one way according to itself; in another way with respect to us. According to itself a certain proposition is said to be known in itself whose predicate comes from the definition of the subject; it does happen, however, that such a proposition will not be known in itself to one ignorant of the subject. As in this proposition, 'man is a rational being', it is known in itself according to its own definition because he who says 'man' says 'rational being', and yet to one ignorant of what a man is, this proposition is not known in itself.^[203]

Just as being and the principle of non-contradiction are the primary concepts for theoretical wisdom, goodness and its function as the end of action direct practical knowledge. Practical wisdom's basis in the concept of goodness produces the primary legal precept that good should be done and evil avoided. All other legal commands which human reason apprehends have their foundation in this simple precept. As there is an order of natural inclinations, there is also one for legal precepts. The basic inclination of human nature is the desire for its own preservation. Then follows the natural desire to communicate with other living beings, which leads to the natural consequences of the union of male and female, the education of the young, and similar practices. The third natural inclination is the desire to know the truth about God, to live in society and to avoid offending others in the community.^[204]

All virtuous acts insofar as they are virtuous pertain generally to the law of nature because the natural law considers everything to which a human being is inclined naturally. The rational soul determines human nature and therefore human beings tend to act according to reason, which is the determining factor of virtue. All virtuous acts come from the natural law since reason naturally directs everyone to act virtuously.^[205] This natural inclination to act rationally is common to all human beings, regardless of political, religious or geographical differences. The variety of moral practices that arise in different societies does not originate in any common precepts of natural law, but rather in the reasoning process to particular choices. With respect to universal principles, whether speculative or practical, there is the same truth or rectitude that can be known by all.^[206]

The common principles of natural law can neither be changed nor abolished, although they may be negated in a particular action when passion or desire may impede its application to the particular act. Thomas does allow for some variability in secondary precepts of natural law that are derived from universal principles, such as the acceptance of thievery by some Germanic tribes. This contravention against the natural law Thomas attributes to depraved customs and corrupt habits.^[207] The failure to recognize the prescription against thievery occurs from the inability to connect a derived precept (do not steal) from the universal principle (do not harm another).^[208]

The natural law is a reflection of eternal law, which, in turn, reflects divine wisdom. Divine wisdom is evident in every created thing because “the nature of divine wisdom moving everything to its proper end achieves the nature of law. The eternal law, therefore, is nothing other than the nature of divine wisdom which directs every act and motion.”^[209]

Thomas’ final solution clearly offers a vision of human purpose and of the moral end that differ from those of Aristotle.^[210] Thomas, like his medieval contemporaries, has ultimately rejected the ethics of practical wisdom for a religious morality based upon eternal divine principles. Whereas Aristotle locates the origins of ethical behavior in the innate ability to imitate the best practitioners of virtues, Thomas grounds moral behavior in “certain principles naturally known… which are the certain seeds of the intellectual and moral virtues” and in the will’s natural appetite to recognize these principles as good.^[211] The transition from an ethics of practical wisdom is complete, since prudence according to medieval authors demands logical deductions from universal principles to specific conclusions. In the moral theory of Thomas Aquinas the man of practical wisdom can no longer determine the best life to pursue, since the commands of natural law have been determined innately in every human being. The function of prudence is to follow in individual decisions the order of law. As Lottin rightly observes, Thomas calls prudence right reason because it is the imperium of practical reason. This command can be viewed as correct only insofar as it conforms to the principles that ultimately are the norms of morality because of their participation in the eternal law, or ratio divina.^[212] The ability of Aristotle’s phronimos to determine new courses of action and better modes of conduct differs from the virtue of the Christian prudens who accepts eternal commands and aligns the will according to their dictates. As a result, the hierarchical order of human actions determines infallibly the proper choices leading to the perfection of the soul. The practical life is subjugated to the intellectual, but all actions must be in accord with love for God. No human being can determine the relative importance of particular pursuits, since divine and eternal law command how all should act. The flexibility and practicality of Aristotle’s ethics has given way to the universal codes of Christian morality.