Part I History of Ethics
Life of Socrates
Part II Concepts and Problems
Normative Ethics and Applied Ethics
Part III Applied Ethics
Field of Applied Ethics
Excerpts from Norman Kretzmann and Eleonore Stump's entry on Aquinas in the Routledge Encyclopedia of Philosophy (General Ed. Edward Craig)
Thomas Aquinas (1224/6-74)
Aquinas lived an active, demanding academic and ecclesiastical life that ended while he was still in his forties. He nonetheless produced many works, varying in length from a few pages to a few volumes. Because his writings grew out of his activities as a teacher in the Dominican order and a member of the theology faculty of the University of Paris, most are concerned with what he and his contemporaries thought of as theology. However, much of academic theology in the Middle Ages consisted in a rational investigation of the most fundamental aspects of reality in general and of human nature and behaviour in particular. That vast domain obviously includes much of what is now considered to be philosophy, and is reflected in the broad subject matter of Aquinas' theological writings.
The scope and philosophical character of medieval theology as practised by Aquinas can be easily seen in his two most important works, Summa contra gentiles (Synopsis [of Christian Doctrine] Directed Against Unbelievers) and Summa theologiae (Synopsis of Theology). However, many of the hundreds of topics covered in those two large works are also investigated in more detail in the smaller works resulting from Aquinas' numerous academic disputations (something like a cross between formal debates and twentieth-century graduate seminars), which he conducted in his various academic posts. Some of those topics are taken up differently again in his commentaries on works by Aristotle and other authors. Although Aquinas is remarkably consistent in his several discussions of the same topic, it is often helpful to examine parallel passages in his writings when fully assessing his views on any issue.
Aquinas' most obvious philosophical connection is with Aristotle. Besides producing commentaries on Aristotle's works, he often cites Aristotle in support of a thesis he is defending, even when commenting on Scripture. There are also in Aquinas' writings many implicit Aristotelian elements, which he had thoroughly absorbed into his own thought. As a convinced Aristotelian, he often adopts Aristotle's critical attitude toward theories associated with Plato, especially the account of ordinary substantial forms as separately existing entities. However, although Aquinas, like other medieval scholars of western Europe, had almost no access to Plato's works, he was influenced by the writings of Augustine and the pseudo-Dionysius. Through them he absorbed a good deal of Platonism as well, more than he was in a position to recognize as such.
On the other hand, Aquinas is the paradigmatic Christian philosopher-theologian, fully aware of his intellectual debt to religious doctrine....
Will and action
... Aquinas' concern with moral issues is even greater than his considerable interest in epistemological issues, and his ethics is so fully developed that he integrates his systematic treatment of acts of will into it rather than including such a treatment in his philosophy of mind.
As intellect is the cognitive faculty of the distinctively human rational soul, so will is its appetitive faculty. Will's metaphysical provenance is more primitive than intellect's; it is merely the most subtle terrestrial instantiation of an utterly universal aspect of creation. Not only every sort of soul but absolutely every form, Aquinas maintains, has some sort of inclination essentially associated with it; and so every hylomorphic thing, even if inanimate, has at least one natural inclination: 'on the basis of its form, fire, for instance, is inclined toward a higher place, and toward generating its like' (Summa theologiae Ia.80.1c). Inclination is the genus of appetite, and appetite is the genus of will. The human soul of course involves natural appetites - for example, for food - but its sensory and intellective modes of cognition bring with them sensory appetites, or passions - for example, for seafood - and rational appetite, or volition - for example, for food low in fat content.
In human beings, sensory appetite, or 'sensuality', is a cluster of inclinations (passions) to which we are subject (passive) by animal nature. Following an Aristotelian line, Aquinas thinks of sensuality as sorted into two complementary powers: the concupiscible - pursuit/avoidance instincts - and the irascible - competition/aggression/defense instincts. With the former are associated the emotions of joy and sadness, love and hate, desire and repugnance; with the latter, daring and fear, hope and despair, anger.
For philosophy of mind and for ethics, one important issue is the manner and extent of the rational faculties' control of sensuality, a control without which the harmony of the human soul is threatened and morality is impossible - especially in Aquinas' reason-centered ethics with its focus on virtues and vices. A human being who is not aberrantly behaving like a non-rational animal 'is not immediately moved in accordance with the irascible and concupiscible appetite but waits for the command of will, which is the higher appetite' (Summa theologiae Ia.81.3c). But the kind of control exercised by a cognitive rational faculty (standardly identified in this role as 'practical reason' rather than the broader 'intellect') is less obvious, and is particularly interesting in view of Aquinas' account of intellective cognition. The rational faculties can direct the attention of the external senses and compensate to some extent for their malfunctioning, but they cannot directly control what the external senses initially perceive on any occasion. On the other hand, sensuality and the internal senses are not directly related to mind-independent external things, and so to some extent 'they are subject to reason's command', although they too can fight against reason (Summa theologiae Ia.81.3, ad 3). Elaborating an Aristotelian theme (Politics I, 2), Aquinas observes that the soul's rule over the body is 'despotic': in a normal body, any bodily part that can be moved by an act of will will be moved immediately when and as will commands. But the rational faculties rule sensuality 'politically', because the powers and passions that are the intended subjects of this rational governance are also moved by imagination and sense, and so are no slaves to reason. 'That is why we experience the irascible or the concupiscible fighting against reason when we sense or imagine something pleasant that reason forbids, or something unpleasant that reason commands' (Summa theologiae Ia.81.3, ad 2).
According to Aquinas, the volition for happiness in general is an ineluctable part of human nature. Nonetheless, 'the movement of a creature's will is not determined in particular to seeking happiness in this, or in that' (Quaestiones disputatae de veritate)...
Ethics, law and politics
Aquinas' moral theory is developed most extensively and systematically in the Second Part of Summa theologiae. â Like almost all his predecessors, medieval and ancient, Aquinas sees ethics as having two principal topics: first, the ultimate goal of human existence, and second, how that goal is to be won, or lost. ...
Summa theologiae IaIIae.1-5, sometimes called the Treatise on Happiness, develops an argument to establish the existence and nature of a single ultimate end for all human action, or, more strictly, the kind of behaviour over which a person has 'control'. First, 'all actions that proceed from a power are caused by that power in accordance with the nature of its object. But the object of will is an end and a good', that is, an end perceived as good by the willer's intellect (Summa theologiae IaIIae.1.1c). From this starting point Aquinas develops an argument designed to show that a human being necessarily (though not always consciously) seeks everything it seeks for its own ultimate end, happiness.
Aquinas argues that the often unrecognized genuine ultimate end for which human beings exist (their 'object') is God, perfect goodness personified; and perfect happiness, the ultimate end with which they may exist (their 'use' of that object), is the enjoyment of the end for which they exist. That enjoyment is fully achieved only in the beatific vision, which Aquinas conceives of as an activity. Since the beatific vision involves the contemplation of the ultimate (first) cause of everything, it is, whatever else it may be, also the perfection of all knowledge and understanding (Summa theologiae IaIIae.1.8; 3.8).
Aquinas devotes just four questions of Summa theologiae IaIIae (18-21) to 'the goodness and badness of human acts in general'. ...
What makes an action morally bad is its moving the agent not toward, but away from, the agent's ultimate goal. Such a deviation is patently irrational, and Aquinas' analysis of the moral badness of human action identifies it as fundamentally irrationality, since irrationality is an obstacle to the actualization of a human being's specifying potentialities, those that make rational the differentia of the human species. In this as in every other respect, Aquinas' ethics is reason-centred:
In connection with human acts the words 'good' and 'bad' are applied on the basis of a comparison to reason, becauseâ a human being's good is existing in accordance with reason, while what is bad for a human being is whatever is contrary to reason. For what is good for any thing is what goes together with it in keeping with its form, and what is bad for it is whatever is contrary to the order associated with its form. (Summa theologiae IaIIae.18.5c)
It would be a mistake, however, to suppose that Aquinas takes moral evil to consist in intellective error. Because of the very close relationship he sees between intellect and will, the irrationality of moral wrongdoing will be a function of will as well, not just of intellect. In Aquinas' view, the moral evaluation of a human action attaches primarily to the 'internal act', the volition from which the external act derives. Since 'will is inclined toward reason's good [the good presented to will by intellect] by the very nature of the power of will', bad volition stems from defective deliberation (Summa theologiae IaIIae.50.5, ad 3). As intellect and will continually influence each other, so bad deliberation can also be an effect of bad volition. Moreover, practical intellect's mistakes in identifying the best available course of action may also have the passions of the sensory soul as sources.
... Habits of will are conditions necessary for our carrying out our volitions in particularly good or particularly bad ways, as regards both the 'executive' and the 'determining' aspects of volition; and the habits that play these crucial roles in Aquinas' moral theory are the virtues and the vices.
The four 'cardinal virtues' can be understood as habits of this sort. Reason's habit of good governance generally is prudence; reason's restraint of self-serving concupiscence is temperance; reason's persevering despite self-serving 'irascible' passions such as fear is courage; reason's governance of one's relations with others despite one's tendencies toward selfishness is justice. Aquinas' normative ethics is based not on rules but on virtues; it is concerned with dispositions first and only then with actions. In addition to the moral virtues in all their various manifestations, Aquinas also recognizes intellectual virtues that, like the moral virtues, can be acquired by human effort. On the other hand, the supreme theological virtues of faith, hope and charity cannot be acquired but must be directly 'infused' by God. ...
Passions, virtues and vices are all intrinsic principles, or sources, of human acts. However, there are extrinsic principles as well, among which is law in all its varieties. Consequently, Aquinas moves on in Summa theologiae IaIIae.90-108 to his Treatise on Law, a famous and original treatment of the subject. The best-known feature of the treatise is Aquinas' concept of natural law. Law in general is 'a kind of rational ordering for the common good, promulgated by the one who takes care of the community' (Summa theologiae IaIIae.90.4c), and 'the precepts of natural law are to practical reasoning what the first principles of demonstrations are to theoretical reasoningâ. All things to be done or to be avoided pertain to the precepts of natural law, which practical reasoning apprehends naturally as being human goods' (IaIIae.94.2c). Human laws of all kinds derive, or should derive, from natural law, which might be construed as the naturally knowable rational principles underlying morality in general: ' From the precepts of natural law, as from general, indemonstrable principles, it is necessary that human reason proceed to making more particular arrangementsâ [which] are called human laws, provided that they pertain to the definition (rationem) of law already stated' (IaIIae.91.3c). As a consequence of this hierarchy of laws, Aquinas unhesitatingly rejects some kinds and some particular instances of human law, for example: 'A tyrannical law, since it is not in accord with reason, is not unconditionally a law but is, rather, a perversion of law' (IaIIae.92.1, ad 4). Even natural law rests on the more fundamental 'eternal law', which Aquinas identifies as divine providence, 'the very nature of the governance of things on the part of God as ruler of the universe' (IaIIae.91.1c).
Copyright: Routledge Encyclopedia of Philosophy, Version 1.0, London: Routledge