Ethics, Politics, and the Common Good

Aristotle identifies politics as the chief architectonic science, as it deals with the ultimate end of human life. Yet this description is given at the beginning of the Ethics. Indeed, ethics and politics are intimately connected. In order to understand this relation fully, we must determine how they are distinct with regard to their origin, method, and end. Once properly distinguished, the conclusion follows that politics makes use of the principles of ethics, but for a greater and more noble end, the common good.

Ethics
In beginning of the Ethics, Aristotle discusses the ultimate end of man:

If, then, there is some end of the things we do, which we desire for its own sake (everything else being desired for the sake of this), and if we do not choose everything for the sake of something else (for at that rate the process would go on to infinity, so that our desire would be empty and vain), clearly this must be the good and the chief good[...] We must try, in outline at least, to determine what it is, and of which of the sciences or capacities it is the object. It would seem to belong to the most authoritative art and that which is most truly the master art. And politics appears to be of this nature… (NE I.2)

Aristotle then lays out the method of this “most authoritative art” and concludes the first part of the Ethics with a brief discussion of the “chief good.” The chief good is the end of ethics, so ethics may be defined as “the art which is pursued for the sake of man’s ultimate end.” Sometimes Aristotle calls ethics an art, sometimes a science. This dual characterization is possible because ethics is a practical science.
The sciences are divided into the speculative and the practical. The speculative sciences are pursued for the sake of knowledge itself, and thus do not have their end in operation. For example, mathematics is a speculative science, because the process and the conclusions of mathematics are inoperative: That is, perfect mathematics does not involve praxis. The method of the speculative sciences is resolutory, which means that knowledge proceeds from effect to cause, resolving complex truths into simple truths. For example, the mathematician may deduce a single function from a complex set of discrete data.
The practical sciences, on the other hand, are ordered to operation. For example, carpentry involves a method and acquisition of knowledge, but carpentry is not complete if it does not involve the activity of making things from wood. The method of the practical sciences is compository, which means that they proceed from simple to complex truths. For example, a carpenter, knowing that the height of a 45-degree angle is identical to its width, discerns the correct pitch of a roof and decides to cut the webs at equal lengths.
Ethics is a science that is, in a sense, both speculative and practical, and therefore its method is variable. In ethics, one may resolve complex truths into the simple, such as when one derives from the relationship of persons the principle of justice. But the speculative aspect of ethics is subordinated to the practical: That is, the principles derived in ethics must be put into practice in particular cases. In other words, ethics is not complete if it is not practiced, and so it is primarily a practical science. Therefore, ethics is a science insofar as it involves the attainment of knowledge, and an art insofar as this knowledge is put into practice.
Every art is done for some end, and the end of ethics is happiness. Aristotle defines happiness as, “an activity in accordance with virtue,” especially “the highest virtue… of the best part in us.” We know that the intellect is the best part of man because it is by his intellect that he participates in the natural law and is able to become virtuous at all. Moreover, the intellect is what distinguishes man apart from the other animals; it is the intellect which is the most human part of him. Thus the activity of the intellect, which is the contemplation of truth, is man’s greatest happiness, and the end of the virtuous life.

Politics
So, how does politics differ from ethics? Aristotle notes in the beginning of the Politics: “Observation shows us, first, that every polis is a species of association, and, secondly, that all associations come into being for the sake of some good -- for all men do all their acts with a view to achieving something which is, in their view, a good.” Therefore, as the good is the end of ethics, the good of the community is the end of politics.
The method of political science is also similar to that of ethics. Politics is a practical science, as St. Thomas explains, “since the practical sciences are distinguished from the speculative sciences in that the speculative sciences are ordered exclusively to the knowledge of the truth, whereas the practical sciences are ordered to some work, [politics] must be comprised under practical philosophy, inasmuch as the city is a certain whole that human reason not only knows but also produces.”
Because politics is a practical science, its method is therefore, like ethics, compository. Thomas explains, “since human reason has to order not only the things that are used by man but also men themselves, who are ruled by reason, [politics] proceeds in either case from the simple to the complex.” However, though the method of politics as a science is similar to that of ethics, the practice of politics as an art is quite different. Because it is ordered not to the happiness of one person, but to the happiness of the whole community, it is necessary to have political activity beyond the scope of ethics.
Aristotle notes that most men are not capable of pursuing a moral education because they are not well disposed to practice virtue by their own inclination. And, though a man be eager to pursue the good, and learns how he might attain it, he will not attain the good until he acts. Likewise, St. Thomas observes:

A man needs to receive this training from another, whereby to arrive at the perfection of virtue. And as to those young people who are inclined to acts of virtue, by their good natural disposition, or by custom, or rather by the gift of God, paternal training suffices, which is by admonitions. But since some are found to be depraved, and prone to vice, and not easily amenable to words, it was necessary for such to be restrained from evil by force and fear, in order that, at least, they might desist from evil-doing, and leave others in peace, and that they themselves, by being habituated in this way, might be brought to do willingly what hitherto they did from fear, and thus become virtuous. Now this kind of training, which compels through fear of punishment, is the discipline of laws. Therefore in order that man might have peace and virtue, it was necessary for laws to be framed… (ST Ia-IIae, q.95, a.1)

Hence the activity of political art has two chief characteristics; the didactic, which educates citizens in virtue, and the coercive, which disciplines citizens in the practice of virtue.

Law
This dual activity of politics is called government, and is done by way of legislation (the creation of laws). Law in general has four essential characteristics; it is “[1] an ordinance of reason [2] for the common good, [3] made by him who has care of the community, and [4] promulgated.” The natural law governs all moral activity, as it is the rational creature’s participation in the Eternal law. Politics, however, makes use of human law.
The human law manifests the dual method of moral science; its resolutory derivation of principles and compository application to particular cases. As Thomas explains:

Something may be derived from the natural law in two ways: first, as a conclusion from premises, secondly, by way of determination of certain generalities. The first way is like to that by which, in sciences, demonstrated conclusions are drawn from the principles: while the second mode is likened to that whereby, in the arts, general forms are particularized as to details[…] Accordingly both modes of derivation are found in the human law. But those things which are derived in the first way, are contained in human law not as emanating therefrom exclusively, but have some force from the natural law also. But those things which are derived in the second way, have no other force than that of human law. (ST Ia-IIae, q.95, a.2)

Thus, the human law is a rational participation in the natural law, and is therefore an ordinance of reason.
But, while the natural law is a participation in the eternal law promulgated by God, the human law is promulgated by human authority. Thus there is a distinction between ethics and politics in its relationship to authority. The man who acts virtuously obeys the natural law from God. But citizens are also bound to obey laws that are enacted by human authority in the art of politics. Human authority participates in God’s authority insofar as it derives its principles from the natural law and seeks to attain the end for which the natural law itself is promulgated.

The Common Good
Ethics and politics are further distinguished in their relation to the end for which all law is promulgated. Ethics instructs man in virtue, the end of which is his own happiness. But because virtue is necessarily in accord with the natural law, it also contributes to the common good. Yet ethics is concerned with human acts and happiness simply. Politics, on the other hand, governs the whole community with the explicit end of attaining the common good. Therefore, the greatest distinction between ethics and politics is their relation to the common good. So, in order to understand this distinction well, the common good itself must be well understood.
The common good is called “common” because it is participatory. Strictly speaking, every good is common insofar as it is participatory, as Thomas says, “in the whole created universe there is not a good which is not such by participation.” This is not to say that there is no such thing as a “private good,” but that every good is ordered to some end, and to have a good is to participate in this order.
The common good is therefore defined as the good of the whole for which its parts are ordered. Because the common good is the end toward which its members participate, it is manifested primarily in the peace and order of its members. The most immediate example of the common good is the end of the domestic household; the peace and order of the family. For the peace of the family, the husband must provide for the good of his wife and children, the wife must care for her husband and children, and the children must respect one another and obey their parents. Each well-lived role has the character of virtue, and redounds to the happiness of each person, but the end of domestic virtue is not the happiness of any one person, but of the whole household.
Because all personal goods are ordered to the common good, the common good is better. The primacy of the common good over that of one person is summarized by Aristotle:

If the end is the same for a single man and for a state, that of the state seems at all events something greater and more complete whether to attain or to preserve; though it is worth while to attain the end merely for one man, it is finer and more godlike to attain it for a nation or for city-states. (NE I.2, 1094b)

The primacy of the common good over the personal is not quantitative but categorical. That is, the common good is not the total sum of all personal goods: A pie, for instance, is not the common good of all who have a slice, because each slice that is taken from the pie diminishes the good available to others. Rather, the common good only increases by added participation; as the citizens grow in number and virtue, so grows the peace and order of the city.
That the common good is greater and prior to personal good does not imply that the common good is detrimental to the person. As Aristotle explains, it is quite the contrary:

The city is prior in the order of nature to the family and the individual. The reason for this is that the whole is necessarily prior to the part. If the whole body is destroyed, there will not be a foot or a hand, except in the ambiguous sense… All things derive their essential character from their function and their capacity; and it follows that if they are no longer fit to discharge their function, we ought not to say that they are still the same things, but only that, by an ambiguity, they still have the same names. (Pol I.2, 1253a18)

That is, a single person cannot attain the good apart from the whole to which he is ordered. Man, being a political animal by nature, attains his good by participation in the community of which he is a part. As Charles De Koninck argues, the common good is in fact each man’s highest good:

The highest good of a man belongs to him not insofar as he is himself a certain whole in which the self is the principal object of his love, but "insofar as he is part of a whole," a whole which is accessible to him because of the very universality of his knowledge[…] Thus it is indeed as part that we are ordered to this greatest of all goods which can only be ours most completely through being communicable to others. (De Koninck, 30)

The community to which man is ordered is not limited to the civitas. There is a variety of common goods which exist in a hierarchy, as there is of particular goods, and the degree to which man participates in each good determines its greatness. Therefore, God Himself is the greatest common good, because man participates in God by virtue of his very being.

Objections to the Primacy of the Common Good
We will consider three objections against the common good’s primacy over the person. Firstly, though politics is necessary for the governance of the human community, the individual who is well disposed to contemplate needs no human governance. The contemplative man has attained moral excellence and is led by his own knowledge. Thus, it would seem that the act of contemplation falls outside the purview of politics. Secondly, while it is necessary to pursue virtue in communion with others, contemplation itself is a solitary act, and so the highest good for the person is not the common good. Thirdly, appeal might be made to the dignity of the person, which is primary to the common good on account of its inviolability. That is, the dignity of the human person cannot be violated for the sake of another good.
To the first objection, we respond that politics is necessary not only because many persons are ill-disposed to pursue virtue by their own inclination, but because participation is impossible without an external governing principle. The good of the whole, as its end, is external to whatever participates in it. For example, the good of a man, though it involves a well-functioning hand, is not limited to the good of the hand itself: A man’s good is external to the good of his hand, because his hand is ordered to the good of the whole man. Moreover, because the good of the whole man is external to that of his hand, his hand is incapable of attaining this external good of its own principle.
Therefore, even if every member of the community were perfect in virtue, an external governing principle would be necessary to attain peace and order, as Etienne Gilson summarizes:

This or that man’s reason, though qualified to guide his actions for his welfare, is not, therefore, qualified to shape them for the good of the community to which he belongs, and to subordinate them to it. Here is the basis of the exteriority, so far as the individual is concerned, of the principle which obliges his activity. Law, then, will express the demands of reason ordering the individual’s life in view of the common good of his group and speaking from the outside in the name of that group. (Gilson, 195)

The exteriority of the human law to each person is a reflection of the natural law from which it is derived. Man’s participation in the eternal law, while it orders him as a part of the Eternal law, is ordered to God Himself, who is external to man.
To the second objection, it should be noted that, though the end of ethics is the contemplation of Truth, contemplation is itself a special participation in the highest Good common to all things. Truth is not made private by man’s grasp of it. Though a solitary act by outward appearance, the activity of man’s intellect is itself a participation in the light of the Divine Intellect. Therefore, when one contemplates, he does not ascend from a good shared by the community to a noble personal good; rather, he ascends from a lesser common good to a greater common good.
To the third objection, we reply that personal dignity itself is derived from participation in the common good. Any attempt to elevate the singular person above the common good of which he is part only diminishes personal dignity, as De Koninck explains:

Through disordered love of singularity, one practically rejects the common good as a foreign good and one judges it to be incompatible with the excellence of our singular condition. One withdraws thus from order and takes refuge in oneself as though one were a universe for oneself, a universe rooted in a free and very personal act. One freely abdicates dignity as a rational creature in order to establish oneself as a radically independent whole. (De Koninck, 35)

To assert that personal dignity is something greater than its source is to say that the part, which is good insofar as it is ordered to the whole, is also good without the whole. This is absurd.

Conclusion
We may therefore conclude that ethics is not distinct from politics as an “individual” rule from a communal rule, but as the practical science of man’s good from the practical science of the common good. Ethics is ordered to the common good implicitly, and politics makes use of the principles of ethics in ordering man to the common good. Therefore, while ethics may be considered to be a “self-sufficient” science with respect to each person, it is essentially a part of politics.

Bibliography
Aristotle. Nichomachean Ethics. trans. David Ross. New York: Oxford University Press, 1998.

Aristotle. Politics. trans. Ernest Barker. New York: Oxford University Press, 1995.

De Koninck, Charles. On the Primacy of the Common Good. 1997. At https://thomasaquinas.edu/pdfs/aquinas-review/1997/1997-dekoninck-common-good.pdf

Gilson, Etienne. Moral Values and the Moral Life: The Ethical Theory of St. Thomas Aquinas. trans. Leo Richard Ward. (reprint by Kessinger publishing).

Oesterle, John A. Ethics: The Introduction to Moral Science. Englewood Cliffs, NJ: Prentice Hall, 1957.

Thomas Aquinas. Commentary on the Nichomachean Ethics. trans. C.I. Litzinger, O.P. Chicago: Henry Regnery Co., 1964. At https://dhspriory.org/thomas/Ethics.htm

Thomas Aquinas. Sententia Libri Politicorum. trans. Ernest L. Fortin and Peter D. O’Neill. At https://dhspriory.org/thomas/Politics.htm

Thomas Aquinas. Summa Theologiae. trans. Fathers of the English Dominican Province. Benziger bros., 1947. At https://dhspriory.org/thomas/summa/index.html.

God vs Evil?

The Problem of Evil forms the basis of a compelling argument against the existence of God. We will consider the argument as formulated by J.L. Mackie in his work, “Evil and Omnipotence.” After analyzing the argument and its implications, we will consider the “Fifth Way” argument posited by St. Thomas Aquinas, which is, in a sense, the converse of Mackie’s argument. While Mackie argues that the presence of evil contradicts the notion that there is a being both omnipotent and good, St. Thomas argues that the ordering of creatures toward their end (which is their good) can only be the work of divine governance. By analyzing Thomas’ argument and its corollaries, it shall be proven that Mackie’s argument from evil does not demonstrate that God’s goodness or omnipotence is impossible.

J.L. Mackie’s Argument
Mackie’s argument is as follows: If there is a being that is both omnipotent and completely good, then it would not allow evil to exist. But evil does exist. Therefore, there cannot be a being that is both omnipotent and good. To fully understand this argument, the terms ‘omnipotent’, ‘good’, and ‘evil’ must all be defined.
According to Mackie, “there are no limits to what an omnipotent thing can do” (Mackie, 305). So, ‘omnipotent’ means ‘having unlimited ability.’ But what is meant by ‘limit’ is yet unclear: In mathematics, for example, the set of all integers is an infinite set, but it is also limited by its definition, so that there are also an infinite many numbers which are not contained in that same set (e.g. all fractions). So, one might argue, for instance, that God’s power is infinite in a sense, but not absolutely.
But this description of omnipotence seems superfluous. A man may be considered “omnipotent” by the same token, because there is no limit to how many things he may do in a day, albeit he will never actually do all of them. To avoid such a trivial definition, we must assert that there is nothing that could prevent God from acting. Hence, ‘omnipotent’ may be defined as ‘having the ability to act without impediment.’
Mackie does not offer a definition of ‘good’ or ‘evil’ per se, but states that “good is opposed to evil, in such a way that a good thing always eliminates evil as far as it can” (Mackie, 305). He implies that the concept of evil as privatio boni is “inconsistent” but does not say why. What he does allow for, however, is a kind of hierarchy of goods.
The most visceral, “basic” evils, such as pain and its antecedents, he calls “first order evils.” Conversely, pleasure is a “first order good.” There are greater goods than pleasure, however, termed “second order goods.” Second order goods, such as virtue, are only possible as a contrast or reaction to first order evils. For example, one cannot be courageous unless there is some evil to oppose by means of courage.
By delineating the hierarchy of goods in this way, Mackie anticipates a classic solution to the problem of evil; namely, that evil must be allowed in order to have a world that contains the greatest possible good. But this solution seems inadequate, because, just as first order evils make second order goods possible, so also do they make second order evils possible. For example, the ability to cause pain provides man with the capacity for unspeakable cruelty. If courage is greater than simple pleasure, then cruelty must be worse than simple pain. Mackie concludes that, since greater evil is made possible alongside greater good, the objection, which asserts that greater goods are made possible by evil, ultimately fails.
Mackie notes that an additional objection may be made, which asserts that free will itself is a third order good. And in order for the will to be free, the possibility of choosing first and second order evils must at least be available to it. Therefore, the objection concludes, God allows even second order evils for the sake of the third order good of freedom.
There are three problems with the assertion that free will is itself a third order good. The first is that the assertion seems arbitrary. If ‘freedom’ is itself a kind of good, then what can be said of a will that “freely” chooses evil? One might claim that a will which chooses evil is no longer free and thus no longer good. But, if a will could destroy its own freedom, is it not therefore the cause of a third order evil; that is, the contrary of a third order good?
The second problem with the notion of free will as a third order good is its reliance on the possibility of evil. If evil is only the result of human free will, then this seems to imply a notion of freedom that is purely arbitrary because, rather than the will determining itself by the character of its own goodness, it acts completely at random. But if free will is random, and not at least self-determined by a will that was created good, then there seems to be no reason to consider free will good at all, as there is no assurance that it will not be the cause of evil.
The third problem with the notion of a free will that requires the possibility of evil is a problem of logic: It is absurd to speak of a “necessary possibility.” A thing is either necessary or it is only possible. If the existence of free will necessitates the existence of evil, then there seems to be no reason why free will should be considered good. If the existence of free will presents merely the possibility of evil, then it is possible for God to create free will and also to prevent evil. And if it were possible for God to create free will without the allowance of evil, then God is responsible for evil.
According to Mackie, asserting that the mere possibility of evil is inherent in a created will creates yet another problem; not with the nature of freedom, in this case, but with the nature of omnipotence. Can God create a free will that cannot choose evil? If He can, then it would seem that the will is only “free” in a trivial sense. And if God cannot, then God’s omnipotence seems to have clear limits.
Thus, Mackie asserts that God’s goodness and omnipotence cannot both coexist with evil. Furthermore, the assertion that free will is a third order good, for which it is necessary to allow evil, seems to create five additional problems: (1) Any increase in good on account of evil is also met with an increase in evil; (2) if free will is a third order good, but can cause evil, then it is also a third order evil; (3) if free will is not determined by good, then neither is free will good; (4) if evil is not a necessary prerequisite for free will, then God is responsible for evil; and (5) it seems contradictory to posit that God can create something which can impede his power.

St. Thomas’ Fifth Way
The “Fifth Way” can be seen as the converse of Mackie’s argument in that it argues for God’s existence on the premise that things desire the good:

We see that things which lack intelligence, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that not fortuitously, but designedly, do they achieve their end. Now whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God (ST Ia, q.2, a.3).

Here, Thomas draws on a clear definition of the good. This definition, however, is multifaceted, as ‘good’ can be said in many ways. In the simplest sense, ‘good’ is a term that is convertible with ‘being.’ Hence, goodness is a necessary attribute of God, because ‘God’ is defined as ‘subsistent Being itself’ (ipsum esse subsistens).
When we speak of specific beings, however, their good is what is essential to their specific being. In this second sense, ‘good’ is a thing’s final cause, because a thing’s final cause is first and foremost its own perfection. For example, the good of a man is to be a perfect man; hence a good man more fully realizes his humanity than a man who is less good.
There is a third sense of ‘good,’ which is participatory good, and is a kind of relation between the first and second senses. Specific beings participate in Being by means of their final cause. For example, a man exists as a man, so the more perfect a man he is, the more fully he participates in Being. Therefore, these three senses of ‘good’ are really three aspects of the same thing, which is Being: The Good is Being itself, which is also the good of the creature, and which the creature attains by its own perfection.
Thomas’ argument observes that even irrational beings pursue and attain their own good. If the movement of things toward their end cannot be attributed to a deliberation on their own part, then it must be attributed to some other principle. The ultimate governing principle of this movement is called God.

Good, Evil, and Omnipotence
We now have two competing arguments, one positing that the existence of evil precludes the existence of God, the other positing that the existence and pursuit of the good requires God’s existence. As Mackie’s argument rests on implicit notions of evil, free will, and omnipotence, we will consider how Thomas understands those same notions. Whether the notions as explained by Thomas can overcome the problems outlined by Mackie will help determine the efficacy of both arguments.
St. Thomas defines ‘Omnipotence’ as “unlimited power,” but a thing can be limited in two ways; namely, by privation and by negation. A thing without limit according to privation is deprived of the limits which it should have by nature. Only mathematical concepts can be unlimited in this way. That which has no limit according to negation cannot have a limit, and only God can be unlimited in this way. In other words, because God is Being, there is nothing in which He is not.
Furthermore, God is pure Act, so there is no imperfection in God and no potency that is not already actualized. With such an understanding of God, we refer to the principle agere sequitur esse (act follows being) and conclude that, because God is ipsum esse subsistens, His power necessarily pervades and contains all existence. Furthermore, this power has both an extension and an intensity which is unlimited by God’s nature. However, His power is more or less efficacious according to the reception of the thing in which He acts.
God’s power has a limited effect in the receiver because of a limit of nature or of disposition. As noted above, specific things participate in being according to their specific natures. Hence, God’s power is manifest in each thing according to the limits of its nature. For example, a tree’s being is not boundless, despite having received it from God, but its being is limited specifically by its being a tree.
The second limit of God’s effect is a thing’s disposition. In a thing considered by itself, there are two powers at work; the power of God by which a thing exists, and the power of the thing’s nature by which it participates in existence. But some other power may corrupt the nature of the thing itself. For example, a tree may be eaten by termites, in which case its subsequent imperfection hinders the effects of God’s power according to its nature.
Because a thing participates in being according to its nature, and the perfection of a thing’s nature is its good, the limit of God’s power according to a thing’s disposition is evil. Hence, evil is defined as privatio boni (the privation of good), and every privation of good is ultimately a privation of being and a limit to the effect of God’s power.
Evil, thus defined, can only be parasitic on the good: It is not directly opposed to the good as a competing power, but is merely a corruption or deficiency in an essentially good nature. Even if one were to point to tangible “phenomenological” evils such as pain or cruelty as evidence that evil is not merely a privation, careful analysis of the evils in question nevertheless reveal some kind of privation. For example, pain is felt in response to some stimulus: If one breaks his foot, he will feel an intense pain. But it would be worse in such a case not to feel pain, otherwise he would not be aware of the severity of his injury. His injury itself is a privation: The integrity and proper function of his foot are lost.
We likewise discover privation in considering second order evils. For example, what we call cruelty is deliberately and unnecessarily causing pain in another. It would seem that a man’s cruelty is a positive evil, because his actions are explicitly and immediately experienced as evil. However, the agent of cruelty does not choose to be cruel for the sake of evil itself, but because he sees in it some apparent good which he desires, such as vengeance or obedience or pleasure.
In every example of evil thus far, we come across a common theme: in every instance of evil, we see not only a parasitic relation to the good, but a derivation of good (real or at least attempted) from evil. The corruption of a tree by termites is good for termites; pain that is a proper response to injury is good; and the man who resorts to cruelty does so out of desire for some good.
Of course, not every good which arises from the corruption of some other good is necessarily greater. If one breaks his own foot to produce the good of a properly responsive pain, he does not better his situation. Nevertheless, it is due to the relation between good and evil that it is at least possible for the presence of evil to give rise to more good than if there were no evil at all. That good is usually produced from evil is especially evident with regard to the order of nature, as St. Thomas says:

Corruption and defects in natural things are said to be contrary to some particular nature; yet they are in keeping with the plan of universal nature; inasmuch as the defect in one thing yields to the good of another, or even to the universal good: for the corruption of one is the generation of another, and through this it is that a species is kept in existence. Since God, then, provides universally for all being, it belongs to His providence to permit certain defects in particular effects, that the perfect good of the universe may not be hindered, for if all evil were prevented, much good would be absent from the universe. A lion would cease to live, if there were no slaying of animals; and there would be no patience of martyrs if there were no tyrannical persecution (ST Ia, q.22, a.2, ad 2).

Therefore, it is not merely possible, but probable that God allows defects in nature so as to multiply good, as the order of nature suggests.
Though “natural” evil may be accounted for by divine providence, there is still the problem of free will as it relates to God’s omnipotence. However, most of Mackie’s contentions about free will are solved by considering what is meant by “free will.” St. Thomas explains how a will is considered free as follows:

Man acts from judgment, because by his apprehensive power he judges that something should be avoided or sought. But because this judgment, in the case of some particular act, is not from a natural instinct, but from some act of comparison in the reason, therefore he acts from free judgment and retains the power of being inclined to various things. For reason in contingent matters may follow opposite courses, as we see in dialectic syllogisms and rhetorical arguments. Now particular operations are contingent, and therefore in such matters the judgment of reason may follow opposite courses, and is not determinate to one. And forasmuch as man is rational is it necessary that man have a free-will (ST Ia, q.83, a.1).

In other words, the will is free when it is determined by reason. Therefore, it may be said that the will is less free insofar as it is affected by a corruption of reason. Furthermore, the use of reason pertains to man’s nature, which is none other than man’s participation in being. Therefore, free will is itself a good insofar as it is essential to man.
If free will is good insofar as it is free, then the presence of evil is not a prerequisite of freedom. It would then follow, according to Mackie, that the primary cause of evil is not human free will, but God. And if God is the primary cause of evil, then God himself cannot be completely good.
However, evil is merely a defect of nature, and has itself no nature or substance. Therefore, evil can only be caused accidentally. Furthermore, a defect can be caused accidentally in two ways; in form and in action. A defect in form results from the agency of some good, such as when termites, in pursuit of their own perfection, destroy the form of a tree. A defect in action results from a deficiency in the agent, such as when a man burns his meal out of ignorance.
Therefore, we may say that God causes certain formal defects accidentally (such as the corruption of things in the order of nature) but, in so doing, we still must maintain that God is absolute Good. A deficiency in action, however, can only be attributed to a being which is capable of corruption, such as man. So, evil which is found in nature as defect or corruption may be attributed to God, who orders corruptible things for the greater good of the whole. But evil that results from a corrupt will can only be attributed to man.
The final contention which Mackie raises is that there is no suitable answer to whether God can create a free will which He cannot control. Such a contention can only be made by equivocating God’s will with the power of created will. Man’s freedom is none other than the determination of his will by his own reason, which is itself a participation in God’s will. Therefore, man’s very nature is an expression of the will of God, Who is its author; and the free act of the will, which follows from man’s nature, is only possible as a participation in God’s will. Were God to override a man’s will, as it were, it would not take the form of violence, but would illumine and strengthen man’s reason and deliberation.
We may conclude then that the first premise of Mackie’s argument is false. If God is both omnipotent and absolutely good, He would allow evil to exist, provided that it result in greater good. Though there is evident evil in the world, it is yet possible for an omnipotent and absolutely good God to allow evil. Moreover, the possibility of bringing greater good out of evil serves as a kind of supplement to the “fifth way”: Not only is the nature of each particular thing ordered to its own good, but even the corruption of particular things may redound to the greater good of the whole order of nature.

Bibliography
Feser, Edward. Five Proofs of the Existence of God. San Francisco: Ignatius Press, 2017.
Mackie, J. L. “Evil and Omnipotence.” In Philosophy of Religion; Selected Readings, ed. Michael Peterson,William Hasker, Bruce Reichenbach, and David Basinger, 304-314. New York: Oxford University Press, 2007.
Thomas Aquinas. Quaestiones Disputate De Potentia Dei. q. 1, a. 2, trans. English Dominican Fathers. Westminster, MD: Newman Press, 1952. At https://dhspriory.org/thomas/QDdePotentia1.htm#1:2
Thomas Aquinas. Summa Theologiae. trans. Fathers of the English Dominican Province. Benziger bros., 1947. At https://dhspriory.org/thomas/summa/index.html.

Why the Human Soul is Immortal (and Animals are Not)

Why does the human soul persist after death whereas the souls of animals do not? In order to answer these questions clearly, we must first define what a soul is and then explore the difference between human and animal souls. To form the basis for our inquiry, we will first prove that all living things have immaterial souls that are distinct from their material bodies and that there are different kinds of souls for the different kinds of living things. Once this basis has been sufficiently laid out, we will focus specifically on whether it is possible for each kind of soul to continue to exist after death. Then of course we will determine whether it is possible for the soul not to exist after death, and by this come to our conclusion that the human soul does indeed persist after bodily death, whereas the souls of animals are destroyed.

We begin with our first question, “what is a soul?” We say that a thing has a soul insofar as it is alive. Life is manifested primarily as nutrition and growth by which something is moved by an intrinsic principle. This power is proper to all living things and is the fullest extent of life in what are called nutritive or vegetative souls (such as plants). In animals, life is also manifested in sensation and directive movement, which is why their souls are called sensitive souls. These two demarcations, vegetative and sensible, are enough to identify three ways in which the soul can be understood in relation to a living thing; viz. as form, as mover (or intrinsic efficient cause), and as end (or final cause).

Aristotle identifies the soul as the form of a living body, which is to say that the soul is what makes a living body what it is. This is not merely a definition of life, that a soul is merely what it means to be alive. Rather, the soul subsists as the actuality of a living body.¹ This means that what is potentially alive is made actually alive by its soul. This also accounts for the integrity of individual living things, as the form is what gives the material elements of a thing the status of parts of a whole.² With regard to motion, Aristotle identifies desire as the primary principle of motion and attributes this to sensible souls.³ There is also motion in the sense of nutrition and growth in vegetative souls and, for our present purpose, it is enough to mention that vegetative souls, while possessing neither a desire prompted by the senses nor the deliberation of reason, they are still inclined to motion with respect to nutrition and growth. Thus all living things are moved internally by a function or part of their souls. With regard to the end, Aristotle identifies the primary end of a living thing as the soul itself.⁴ This is simply to say that the goal of all living things is to live. Because such things are body-soul composites, they are bound to corruption and death. Hence in order to attain the end of life (no pun intended) they are generative, producing things like themselves in species, thereby continuing life specifically, though individually it dies. This necessitates a body in order for subsistence and generation to take place, albeit the body is in this regard a means to the end.⁵

By acknowledging these three roles, it might seem that the soul is some emergent property or function of material arising out of a material cause. We will consider four arguments which support this. Firstly, if the soul is the form of the body, then the soul only exists insofar as it informs the body. Therefore, it is reasonable to infer that the soul is something dependent on the body.⁶ Secondly, if souls are identified according to their activity (as a vegetative soul vegetates and a sensible soul senses) then we ought to consider them precisely to be activities and nothing more. For what we observe in living things are not souls as such, but vegetation and sensation, by which we infer that there is something other than what we observe which performs those activities. But this is an unnecessary abstraction, as we perceive nothing other than activity in a material body.⁷ Thirdly, if the soul is the principle of movement in material things, then it interacts with material. But what is immaterial is impassible and cannot interact with what is material. Therefore the soul must not be immaterial but something material. Finally, the end of a living thing is to preserve its life. But self-preservation is achieved in and through the preservation of the body. Therefore, life-as-end is not distinct from the body but is merely the integrity of the body and its functions.

Against the first argument, we should note that if we regard the form as dependent on matter as a kind of supervening quality, then we would subvert the order of substance and accidents. What is accidental to a thing is secondary to what the thing primarily is, which is its substance. When the soul is called the form of the body, it is precisely meant as the substantial form. Even though matter is a necessary part of a natural living thing, the matter is not enough to identify that thing as what it is, as we see that a plant or animal can grow and diminish over time while maintaining its individuality. But to say that a living thing's soul exists only insofar as it has matter is to put accidents prior to substance or else make matter the substantial form of the body, which is absurd. Hence, if we wish to concede that there are individual living things, then the primacy of the soul is a necessary conclusion from what is perceived.⁸

To the second argument, we can build on our first reply. We ascertain the form of a thing when we identify what it is specifically (i.e. according to a species), for matter is informed according to its species by its form. This is not merely a logical device, for to refer to a substantial form is to say that there is some active principle in that living thing which unifies the parts into a whole. Now when we observe some activity in a certain thing, we can attribute that activity in two ways; to the part in which the activity is manifested, and to the whole to which the part belongs. E.g. when a worm is prodded, we may say that there is a reaction in certain material parts of that worm, and that what we observe is the action of material apparata in response to some material stimulus. This may be true with respect to chemistry, but it is ultimately unintelligible without respect to the thing acting, viz. the worm. If we cannot account for the substantial form of the worm, then we cannot say that the worm moves, but only that the parts of the worm move. But this is an unnecessary reduction, whereas it is reasonable to attribute the movement observed within a thing to the thing itself.

To the third argument, it would indeed seem that immaterial things cannot interact with material for two reasons; viz. that what is material cannot harm or hinder what is immaterial (e.g. we cannot tie down an angel or transplant a soul) and that there is no known mechanism which would explain how such an interaction could take place. But we should not form too simple a concept of immaterial things. Some tend to think of interaction in terms of bodies responding to touch, like two rocks hitting together. But no interaction at all can be attributed to purely material causes. The rocks that one knocks together are being moved ultimately by something that does the moving. So the answer to the question, how does the immaterial interact with the material, is found in the question, “what is interaction?” Strictly speaking, “pure matter” does not act. To hold this would ultimately be to conflate material cause and efficient cause and to disregard the act-potency distinction altogether. Therefore we must concede that there is something immaterial in a living thing which is the principle of its action.

In response to the fourth argument, it should suffice to say that, having proved the existence of the soul as the substantial form of a living thing, the body is the matter which is informed by the soul, and through such the soul acts. Thus the integrity of the body is due to the soul's act, which works in and through the body as the means to preserve its proper place as form. Because preservation of life is attained through the body, it does not follow that the life of the body is the body itself.

It should now be clear what the soul is; the substantial form of a living being, as well as its active principle, accounting for its growth and sensation, with the end of subsisting itself and in generating life according to its same species. This account of the soul suffices for all animals except man, whose soul is rational in addition to the aforementioned qualities. As mentioned above, the soul (as form) informs matter to participate in a given species. According to Aristotle, a species is nothing other than some member of a genus which is distinguished by means of some difference.⁹ The essence of man is the composite of his form and (indeterminate) matter and is expressed by its definition.¹⁰ This means that the definition of man is precisely a description of his differentiation as a species within his genus. Hence we define man as “rational animal,” in the genus “animal” and differentiated from other animals by his rational intellect. This leaves us with three kinds of souls altogether; vegetative, sensible, and man's, which is called the rational soul.

As we have said, the difference between a man's soul and an animal's soul is in the intellect. So if there is a difference between sensible and rational souls in their ability to survive death, then it must be on account of the intellect. But whether the sensible soul can survive death is still to be determined. In order to understand how the material destruction of a thing can effect its substantial form, it is helpful to understand that there is a kind of hierarchy of forms, owing to their relation to the matter in which they act, as St. Thomas says:

[I]t must be considered that a gradation of forms in the order of operation corresponds to the gradation of forms in the order of existence, for an operation is an act of an agent in act. Therefore the greater perfection a form possesses with respect to conferring the act of existing, so much the greater is its power of operating. Hence more perfect forms have a greater number of operations and more diverse ones than less perfect forms (DA 9 resp.).¹¹

Thus we have varying levels of forms corresponding to different levels of perfection; material forms (such as the form of bronze), the forms of living things, the forms of sensible animals, and the rational form found in human beings.¹² So we should note that an animal has perfections according to their material being, their being alive, and their being an animal, and a man specifically has one more perfection, that of being rational.

That a being has several formal perfections does not necessitate its having several souls. As explained above, the soul is a substantial form. There can only be one substantial form of any given thing, as the substantial form is precisely what accounts for its being a substance. And a substance is something which is adjoined by accidents, the latter existing in a thing by virtue of the former (we can see an analogous relation between a predicate and its subject). But a (primary) substance cannot be predicated of another substance. So if an individual were to have many souls, he would necessarily be a conglomeration of many substances and hence would not be an individual at all, which is absurd.¹³

It should now be clear that there is a “gradation of forms in the order of operation” in living things, not on account of an accumulation of various forms, but on account of a gradation of power according to each form. For example, the sensible soul is superior to material forms, for the sensible soul not only informs matter but grows and perceives as well. And the rational soul is superior to the sensible, because the rational is able to conceive of immaterial things in the intellect, and this in addition to the powers proper to the sensible soul.

So, having given a precise account of sensible and rational souls as well as their differences, we can now explain why sensible souls cannot survive death. St. Thomas explains this in the following:

[T]hings composed of matter and form are corrupted by losing the form that gives them their act of existing. Moreover a form itself cannot be corrupted in itself (per se), but is corrupted accidentally as a result of the disintegration of the composite, inasmuch as the composite, which exists in virtue of its form, ceases to exist as a composite. This indeed, is the case if the form is one that does not have an act of existing in itself, but is merely that by which a composite exists.¹⁴

Thomas here distinguishes between a form which is the act of existing in a composite (form and matter) and a form which is its own act of existing. We can see how this plays into the question of death by resuscitating our first and fourth objections from above and adding some qualifications. If a certain soul exists only as that which informs some matter, then the soul only exists insofar as it informs the body. Therefore it is necessary that the soul is something dependent on the body, not as an emergent property but in regards to its subsistence. Such a soul subsists in composition with its matter by preserving the integrity of the composite in the matter through which it operates. Thus the disintegration of the composite in death entails the dissolution of that soul which formed the composite. Simply put, the soul of a dog informs some matter as a dog's matter. Everything the dog's soul does is done through in its matter. If you disintegrate the dog then its soul ceases to exist because there is nothing left for there to be a dog.

As noted above, the human soul differs from other animals in his intellect. Man exists as an animal by means of his body, but rationally by means of his intellect. Thomas explains:

Now if there is a form having an act of existing in itself, then that form must be incorruptible. For a thing having an act of existing (esse) does not cease to exist unless its form is separated from it. Hence if the thing having an act of existing is itself a form, it is impossible for its act of existing to be separated from it. Now it is evident that the principle by which a man understands is a form having its act of existing in itself and is not merely that by which something exists. For, as the Philosopher proves in the De anima [III, 4, 429b 3], intellection is not an act executed by any bodily organ.¹⁵

While man's soul shares with other animals the operations proper to their bodies, the operation of his soul in the intellect is distinct from his body. Though man acquires knowledge beginning with the perception of material things by means of his body, all three causes present in his soul (formal, efficient, and final) act in the intellect without the incorporation of matter. His intellect does not exist as any material thing. His act of intellection moves by an intrinsic principle, without material cooperation. And the end of his intellect is not merely the preservation of life, but the attainment of truth, which is ultimately not attained in nor attributable to his matter. Thus we can see that the rational soul does not exist by virtue of its composition with matter, but exists in its own right. Therefore when man's body dies, his soul must survive.¹⁶

1 Aristotle, De Anima in Introductory Readings in Ancient Greek and Roman Philosophy, eds. Reeve and Miller (Indianapolis: Hackett, 2006), 278.

2 ibid.

3 Aristotle, De Anima, 285.

4 Op. cit. 281.

5 Op. cit. 282.

6 Thomas Aquinas, Quaestiones Disputate De Anima, trans. John Patrick Rowan (St. Louis: B. Herder Book Co., 1949), A 14, Obj. 1

7 Op. cit. A 12, Obj. 2

8 Thomas Aquinas, Summa Contra Gentiles, ed. Joseph Kenny (NY: Hanover House, 1957), II.xxvi.3

9 Aristotle, Metaphysics, trans. Joe Sachs (Santa Fe: Green Lion Press, 1999), 998b (pg. 43).

10 Thomas Aquinas, De Ente et Essentia, trans. Armand Maurer (Toronto: Pontifical Institute of Mediaeval Studies, 1968), IV.iii (pg. 36).

11 Aquinas, De Anima, 9 resp.

12 ibid.

13 Aquinas, De Anima, 11 resp..

14 Op. cit. 14 resp.

15 ibid.

16 ibid.

Why the Mind Cannot Err With Respect to Essence

In the Summa Theologica (I, Q 85, A 6), St. Thomas argues that the intellect cannot err with respect to a thing's essence. This seems counter-intuitive, as Thomas himself wrote an entire work on properly understanding essence. So why one cannot err in apprehending essence is not entirely clear. In order to understand what is meant by his claim, we will determine what the intellect is, how it operates, what an essence is, and what is meant by error on the part of the intellect. To the question treated in the Summa, we being with the sed contra:

Augustine says (Questions. 83, qu. 32), that "everyone who is deceived, does not rightly understand that wherein he is deceived." And the Philosopher says (De Anima iii, 10), that "the intellect is always true."¹

This gives us a two-pronged approach to the problem. On one hand, there is the proposition that deception implies an imperfect operation of the intellect. On the other hand, there is the proposition that the intellect itself is true by nature. This prompts an account of exactly what the intellect is, for if there is error or deception at all, it would seem to be on account of the intellect (as is stated in objections 1 and 2 of the same question).²

The intellect is understood as being passive in that it is predisposed to what is intelligible, as Thomas explains, “[T]he human intellect, which is the lowest in the order of intelligence and most remote from the perfection of the Divine intellect, is in potentiality with regard to things intelligible, and is at first 'like a clean tablet on which nothing is written,' as the Philosopher says.”³ Aristotle likewise compares the intellect to the senses because of its passivity to external objects. But neither intellect nor sense is purely passive. Though the senses receive impressions from external objects, they are passive only in that they are potentially receptive to their proper objects.⁴ In a similar way, the passive intellect receives external objects, and is potential to them in the sense that it must lack the natures which it apprehends, as Thomas explains, “if the intellect were restricted to any particular nature, this connatural restriction would prevent it from knowing other natures.”⁵ We can see this analogously in the eye: It is incorrect to say that the eye contains light and color by its nature, rather that it is by nature receptive to light and color. Moreover, the intelligible forms which we perceive in matter exist in matter, though matter is not intelligible per se. What makes them intelligible is the power of the active intellect which discerns form from matter by abstraction.⁶ So the intellect, in order to know, must have a nature that is distinct from all the other things that it knows. Therefore, if it can know all sensible things, it must be distinct from any sensible nature. This precludes any notion of the intellect as a bodily organ, which leads us to conclude that the intellect must be something immaterial.⁷

That the intellect is immaterial helps us to understand how it is passive in one respect but active in another. While both intellect and the bodily senses are receptive to their proper objects (not in the same way but analogously), they are each active in different ways. As Thomas explains, “the difference is that sensitivity acts in the body, but the intellect acts on its own.”⁸ We can see this in the effects their proper objects have on their operation: The eye sees by receiving light, so that the material organ is effected by a material object. Too much of its object can overwhelm the organ, as when the eye is blinded by an excess of light. But the intellect is never overwhelmed by “too much truth.” Rather than being blinded or brought low by its object, the intellect is strengthened in its operation such that what was difficult to receive at first makes it see all other objects more easily.⁹ Because the intellect acquires knowledge primarily through the senses, its activity presupposes the activity of the senses. But because the intellect does not of necessity work through some bodily organ, it works by its own intrinsic principle.

As said above, the intellect is receptive to truth as a kind of potency. It acquires knowledge with reference to sensible things, but it works in itself from the self-evident first principles that it possesses by nature. And there are also principles external to a man which can aid in the acquisition of knowledge. So there are two principles involved in the activity of acquiring knowledge, extrinsic and intrinsic; extrinsic in what man learns by instruction and intrinsic in what he discovers by his own act. Because the intellect acts by an intrinsic principle, it acts on an active potency.¹⁰ Hence instruction, being an extrinsic principle, is something secondary to the activity of the intellect, and is not necessary for its perfect operation. In order to ascertain whether it is possible for the intellect to err with respect to its own operation, we should focus primarily on the intrinsic principle of knowledge.

Having given an account of the intellect, what it is and by what principle it operates, we have now to explore how the intellect understands its object. We have already mentioned that matter is not in itself intelligible but that the intellect nevertheless understands in connection with the sensitive faculties. While matter itself is not something which the intellect directly apprehends it is perceived through the senses. And it is from its perception through the senses that the intellect creates an image (a phantasm) of what is perceived from which it can abstract the intelligible form.¹¹ According to St. Thomas, one can abstract in two ways. One way is to consider something to be separate from that in which it is understood as if they were separate in reality; e.g. if one were to abstract “red” from “surface,” taking the color to be something distinct and separate from colored surfaces. This type of abstraction admits error, because the intellect in this way does not consider things as they are. The second way in which the intellect can abstract is to consider something absolutely, such that we disregard those things which are not necessary to the thing in question; e.g. if we consider “red” apart from “apple,” we are not erroneously understanding what “red” is but regarding “apple” as something unnecessary to redness. Simply put, we may correctly understand “red” by itself as an (accidental) essence, but we cannot understand it as something which exists by itself.¹²

Aristotle's insight into the process of understanding is crucial to forming a complete account of the intellect's operation. In the beginning of the Physics he explains,

[T]he natural road is from what is more familiar and clearer to us to what is clearer and better known by nature; for it is not the same things that are well known to us and well known simply. For this reason it is necessary to lead ourselves forward in this way; from what is less clear by nature but clearer to us to what is clearer and better known by nature. But the things that are first evident and clear to us are more so the ones that are jumbled together, but later the elements and beginnings become known to those who separate them out from these. Thus it is necessary to proceed from what is general to what is particular, for it is the whole that is better known by perceiving, and what is general is a kind of whole since it embraces many things as though they were parts.¹³

So, taking as the object of intellection what is perceived by the senses, the intellect begins its process of coming to know with a general and confused image of things, and from there proceeds by means of abstraction to a more precise knowledge of things in themselves. Thomas expounds on this when he says, “the perfect act of the intellect is complete knowledge, when the object is distinctly and determinately known; whereas the incomplete act is imperfect knowledge, when the object is known indistinctly, and as it were confusedly.”¹⁴ So we refer to the act of the intellect from its active potency as being perfected in the complete and determinate knowledge of its object. But this process is not possible without having a starting point which is found in the first principles.¹⁵ Yet how these first principles are acquired must be explained in order to complete our account of the process of coming to know.

According to Aristotle, the first principles required for knowledge are neither innate, for infants would be as capable of knowledge as a grown man, nor are they acquired at some later point, for learning and discovery would be impossible until then. Because knowledge is acquired through sense-perception, he concludes that the first principles are gathered from sense-perception and the accumulation of memory which, over time, make up experience. Irrational animals have the capacity of both sense-perception and memory, but they are not capable of gathering the principles of knowledge which is a capacity of the intellectual soul.¹⁶ Thomas elaborates on this by reference to the agent intellect, reminding us that the intellect is not merely passive but must actively derive the universal from the experience of particulars.¹⁷

We are now equipped to give a complete account of the intellectual operation in man. A man begins by perceiving sensible objects through his senses (rust, a hard surface, heaviness, etc.). The objects of his senses are unintelligible, but his passive intellect receives an image of the thing perceived and holds this in memory. After many instances of this, the agent intellect is able to abstract from his experience a universal principle (the concept of iron). With the universal now in mind, he is able to proceed to knowledge of particulars (knowing what iron is in general, he can identify particular bodies of iron). It is clear from this that the intellect understands its object by combination and division.¹⁸ This is easily seen with respect to the twofold composition of material things. In one sense a thing is composed of form and matter, in another sense it is composed of substance and accidents. The intellect divides with respect to both these compositions, as our very consideration of them attests, and in combination we acknowledge those composites to be whole in reality.¹⁹

With the intellect and its operations accounted for, we now consider what essence is. Aristotle explains, “a thing's essence is what a thing is.”²⁰ An essence is like a definition, and is indeed expressed by a definition, but is strictly speaking a definition of a thing in its own right, rather than a property or something which can only exist parasitically on something else: E.g. 'man' or 'tree' is an essence but 'white' is not, because 'white' only exists as a property which adheres to man or tree. There are however essential properties of man which are not accidental. “Bipedal”, for instance, is an essential part of 'man'. There is a correspondence here to species, as 'man' is a species of the genus 'animal', and one of the differentiae which distinguishes 'man' from 'cow' is “bipedal,” though “bipedal” itself is not an essence. Aristotle thus concludes, “essence will not be found in any of those things which are not a species of a genus.”²¹

To understand an essence is the same as to identify it. That is, the question, “why is that a man” can be answered by explaining what a man is, and vice versa.²² So, in a general sense, an essence is what a thing is. Depending on what is meant by a “thing” however, there can be a distinction between an essence and a thing. For example, a man is a composite of form and matter. Thus the question “what is a man?” cannot be answered without reference to a body and its constituents. To the question “why is that body a man's body?” the answer will refer to the form which makes the body a man's body. The distinction between the composite and the components points to the substantial form which composes the elements into a whole: E.g. Even though a man by definition has body parts, a collection of body parts is not a man.²³

Essence, in the formulation of its definition, is generally understood with regard to species (though the two terms are not strictly synonymous). A species is a member of some genus which is distinguished from other species of that genus by some difference.; for instance, 'man' is defined as a 'rational animal'. He is generically an animal and specifically rational, 'rational' being the key difference from other animals. It is important to note that man is distinct from animals in species, but not in genus. Man is an animal, albeit a rational one.²⁴ Though there are many men in the species 'man', the species itself is one, as Thomas says,

“[I]t is evident that a multiplicity of parts in a definition does not signify a multiplicity of essential parts of which the essence is constituted as if they were distinct things; but all signify one thing which is made determinate by an ultimate difference. It is also evident from this that there is one substantial form for every species.”²⁵

An essence is expressed by a definition, so that there are many men does not prove that there are many essences or species of man, because where and how many they are does not belong to the definition of man. Neither does the multiplicity of “parts” implicit in the definition (for example man's two legs) mean that there are many essences within an essence, because essence belongs primarily to substance, but each of those so-called parts do not exist as a substance.²⁶ So one could say that there is a definition of “leg” and thus that a leg has in a certain sense an essence, but a leg is not a substance. Furthermore, a leg is defined as part of a body, so it cannot be a leg unless it is subsumed under the essence of the thing to which it belongs.

What we have considered thus far is essence in terms of its definition. But we should consider essence in terms of being as well. As regards to what a thing is in itself, essence is the composite of form and matter.²⁷ It is by its essence that an individual thing participates in being. This is not to say that everything which has an essence also has being, but that all things which exist do so insofar as they have an essence. As noted above, it belongs to the species of material beings to have matter, but not this or that matter. The prerequisite matter for a given species is called indeterminate matter, while the matter by which an individual participates in the species is called determinate. Therefore material things in particular participate in a species through determinate matter and, by the same token, are distinct from other individuals who share the same essence.²⁸ Though essence is the composition of form and matter, neither the form nor the matter are separate in reality, this means that essence cannot be broken into parts: It is understood by combining terms (form and matter, genus and difference, etc.) into a definition, but an essence is a distinct unity in reality.

Now that it is clear what the intellect is and how it operates, as well as what essence is and how it is known, we may at last consider Thomas' argument in full. He recalls the comparison between sense and intellect, viz. that both are always directed to their proper object, adding that, “as long as the faculty exists, its judgment concerning its own proper object does not fail.”²⁹ The senses may be deceived with respect objects that are “common,” such as size or color; e.g. the eye perceives the sun to be yellow and an inch across. The senses may also be deceived with respect to objects in an accidental way; e.g. salt may be mistaken for sugar. With common objects, the eye is deceived because what is perceives is other than what it is, as the sun is not yellow nor an inch across. With the latter case (salt and sugar), the eye is not deceived with respect to what it apprehends, for it takes the salt to be white and translucent, but is deceived in conflating its object with what appears to be an identical object but is in fact different. In both of these cases, one's sight functions perfectly; it apprehends precisely what it receives. This is why Thomas says, “as long as the faculty exists, its judgment concerning its own proper object does not fail.”³⁰

The proper object of the intellect is essence (in this instance referred to as quiddity which simply emphasizes the “what” of the thing). As we have said, a thing's essence is what a thing is, and it is something unified which we come to understand as a composition. So, in an absolute sense, we have an essence that is indivisible in reality which is apprehended by the intellect which is immaterial. But in order for the intellect to understand an essence, it must move to its act of knowing by means of combination and division. Thus we have two types of error to consider, the apprehension of an object by the intellect taken absolutely, and the understanding of it in terms of its definition (its intellectual composition). If the intellect is said to err with regard to apprehending something absolutely, as for instance one might be said to err in his understanding of what “space” is, then he does not know what it is. There is nothing complex about this type of “error.” Either one knows it or he does not. In fact, if one does not know “space” then he is not mistaken about it, because there is nothing in his mind to mistake. In this regard, i.e. with things that are apprehended simply, the mind cannot err. It is only in the process of discerning composition, as it pertains to a thing's definition, that the mind can be mistaken; for instance, if one were to regard a circle as a “three-sided figure.” Another way in which the intellect could err is to combine incompatible terms into a definition, as for instance in “rational plant.” The error in both of these examples is attributed either to the mis-attribution of a definition or to the combination of incompatible terms into an attempted definition.³¹ But both of these errors are accidental to intellectual operation. The result of both of these errors is to fail to understand an essence completely.

An analogous way of understanding the truth of intellection is by considering the various levels of “error” with regard to apprehension. For example, a young reader may come across a word never before seen and pronounce it “hoar-is-on.” The mistake is in combining the syllables in a way that misses the meaning of the word. The is no “half-understanding” in this regard; the word is a complete mystery. With help from his teacher, the child learns that the word is “horizon” and suddenly understands completely. In another example, a hunter might mistake an elk for a deer. He does not misapprehend the essence of elk, rather he completely understands the essence of deer and misappropriates it to the wrong sense object. Finally, in a more complex case, one might attempt to define an animal without reference to form or the soul, regarding it as merely mechanical or “purely material.” In this case, it should be said that either he does not understand what an animal is because, while he may understand the parts of its definition, i.e. the terms “matter,” “body,” “life,” “motion,” etc. are correctly apprehended, but they are out placed out of order in that definition. So he does not “half-understand” what an animal is; he does not understand what an animal is at all, though he understands all of the parts necessary to combine a correct definition and come to knowledge of its essence.

It may seem trivial to argue for the truth of the intellect if what is meant is simply that error is only in the process of learning and that substantial ignorance is absolute. But all science (especially philosophy) is at stake if this distinction is not understood properly. The intellect has the power to know the truth, it has the means to attain it, and it knows truth with certainty. That the means of attaining knowledge is prone to fault does not mean that the intellect does not know truth, for to say that the intellect is not true is to say that there is no intellect.

1 ST I, Q 85, A 6 sed contra.(Benziger Bros., 1947)

2 Op. cit. obj 1 & 2

3 ST I, Q 79, A 2 resp.

4 Aquinas, Commentary on De Anima, trans. Foster and Humphries (New Haven: Yale University Press, 1951) 676.

5 Op. cit. 680.

6 ST I, Q 79, A 3 resp.

7 Aquinas, Commentary on De Anima, 681.

8 Op. cit. 688.

9 Ibid.

10 St. Thomas Aquinas, On the Teacher in Thomas Aquinas: Selected Writings, trans. Ralph McInerny (New York, NY: Penguin Books, 1998), 199.

11 ST I, Q 86, A 1 sed contra

12 ST I, Q 86, A 1 resp.

13 Aristotle, Physics in Aristotle’s Physics: A Guided Study, trans. Joe Sachs (New Brunswick: Rutgers University Press, 2011), 33 (1.i).

14 ST I, Q 85, A 3 resp.

15 Physics 99b20

16 Physics 100a4

17 St. Thomas Aquinas, Commentary on the Posterior Analytics, trans. Fabian R. Larcher, (http://dhspriory.org/thomas/PostAnalytica.htm), II, xx.

18 ST I, Q 85, A 5 resp.

19 ST I, Q 85, A 5, ad 3

20 St. Thomas Aquinas, Commentary on the Metaphysics, trans. John P. Rowan, (Chicago, 1961) (http://dhspriory.org/thomas/Metaphysics7.htm), VII, iii, 581.

21 Ibid.

22 Aristotle, Metaphysics in Commentary on the Metaphysics by Thomas Aquinas, trans. John P. Rowan (Chicago, 1961) (http://dhspriory.org/thomas/Metaphysics7.htm), 1651.

23 Commentary on Metaphysics, 1674.

24 Aquinas, Commentary on Metaphysics, 1328.

25 Aquinas, Commentary on Metaphysics, 1339.

26 Op. cit., 1339.

27 Thomas Aquinas, De Ente et Essentia, trans. Armand Maurer (Toronto: Pontifical Institute of Mediaeval Studies, 1968), 36 (IV.iii).

28 De Ente, IV.v

29 ST I, Q 85, A 6 resp.

30 ibid.

31 ST I, Q 85, A 6