Of the Cause of Habits, as to Their Formation

Of the Cause of Habits, as to Their Formation — St. Thomas Aquinas asks: Whether any habit is from nature?; Whether any habit is caused by acts?; Whether a habit can be caused by one act?; Whether any habits are infused in man by God?.

We must next consider the cause of habits: and firstly, as to their formation; secondly, as to their increase; thirdly, as to their diminution and corruption. Under the first head there are four points of inquiry:

Article 1: Whether any habit is from nature?

In Ethic. vi, 6, among other habits, place is given to understanding of first principles, which habit is from nature: wherefore also first principles are said to be known naturally.

One thing can be natural to another in two ways. First in respect of the specific nature, as the faculty of laughing is natural to man, and it is natural to fire to have an upward tendency. Secondly, in respect of the individual nature, as it is natural to Socrates or Plato to be prone to sickness or inclined to health, in accordance with their respective temperaments. Again, in respect of both natures, something may be called natural in two ways: first, because it entirely is from the nature; secondly, because it is partly from nature, and partly from an extrinsic principle. For instance, when a man is healed by himself, his health is entirely from nature; but when a man is healed by means of medicine, health is partly from nature, partly from an extrinsic principle.

Thus, then, if we speak of habit as a disposition of the subject in relation to form or nature, it may be natural in either of the foregoing ways. For there is a certain natural disposition demanded by the human species, so that no man can be without it. And this disposition is natural in respect of the specific nature. But since such a disposition has a certain latitude, it happens that different grades of this disposition are becoming to different men in respect of the individual nature. And this disposition may be either entirely from nature, or partly from nature, and partly from an extrinsic principle, as we have said of those who are healed by means of art.

But the habit which is a disposition to operation, and whose subject is a power of the soul, as stated above (), may be natural whether in respect of the specific nature or in respect of the individual nature: in respect of the specific nature, on the part of the soul itself, which, since it is the form of the body, is the specific principle; but in respect of the individual nature, on the part of the body, which is the material principle. Yet in neither way does it happen that there are natural habits in man, so that they be entirely from nature. In the angels, indeed, this does happen, since they have intelligible species naturally impressed on them, which cannot be said of the human soul, as we have said in the ; .

There are, therefore, in man certain natural habits, owing their existence, partly to nature, and partly to some extrinsic principle: in one way, indeed, in the apprehensive powers; in another way, in the appetitive powers. For in the apprehensive powers there may be a natural habit by way of a beginning, both in respect of the specific nature, and in respect of the individual nature. This happens with regard to the specific nature, on the part of the soul itself: thus the understanding of first principles is called a natural habit. For it is owing to the very nature of the intellectual soul that man, having once grasped what is a whole and what is a part, should at once perceive that every whole is larger than its part: and in like manner with regard to other such principles. Yet what is a whole, and what is a part---this he cannot know except through the intelligible species which he has received from phantasms: and for this reason, the Philosopher at the end of the Posterior Analytics shows that knowledge of principles comes to us from the senses.

But in respect of the individual nature, a habit of knowledge is natural as to its beginning, in so far as one man, from the disposition of his organs of sense, is more apt than another to understand well, since we need the sensitive powers for the operation of the intellect.

In the appetitive powers, however, no habit is natural in its beginning, on the part of the soul itself, as to the substance of the habit; but only as to certain principles thereof, as, for instance, the principles of common law are called the "nurseries of virtue." The reason of this is because the inclination to its proper objects, which seems to be the beginning of a habit, does not belong to the habit, but rather to the very nature of the powers.

But on the part of the body, in respect of the individual nature, there are some appetitive habits by way of natural beginnings. For some are disposed from their own bodily temperament to chastity or meekness or such like.

Article 2: Whether any habit is caused by acts?

The Philosopher (Ethic. ii, 1,2) teaches that habits of virtue and vice are caused by acts.

In the agent there is sometimes only the active principle of its act: for instance in fire there is only the active principle of heating. And in such an agent a habit cannot be caused by its own act: for which reason natural things cannot become accustomed or unaccustomed, as is stated in Ethic. ii, 1. But a certain agent is to be found, in which there is both the active and the passive principle of its act, as we see in human acts. For the acts of the appetitive power proceed from that same power according as it is moved by the apprehensive power presenting the object: and further, the intellective power, according as it reasons about conclusions, has, as it were, an active principle in a self-evident proposition. Wherefore by such acts habits can be caused in their agents; not indeed with regard to the first active principle, but with regard to that principle of the act, which principle is a mover moved. For everything that is passive and moved by another, is disposed by the action of the agent; wherefore if the acts be multiplied a certain quality is formed in the power which is passive and moved, which quality is called a habit: just as the habits of moral virtue are caused in the appetitive powers, according as they are moved by the reason, and as the habits of science are caused in the intellect, according as it is moved by first propositions.

Article 3: Whether a habit can be caused by one act?

The Philosopher (Ethic. i, 7): "As neither does one swallow nor one day make spring: so neither does one day nor a short time make a man blessed and happy." But "happiness is an operation in respect of a habit of perfect virtue" (Ethic. i, 7,10,13). Therefore a habit of virtue, and for the same reason, other habits, is not caused by one act.

As we have said already (), habit is caused by act, because a passive power is moved by an active principle. But in order that some quality be caused in that which is passive the active principle must entirely overcome the passive. Whence we see that because fire cannot at once overcome the combustible, it does not enkindle at once; but it gradually expels contrary dispositions, so that by overcoming it entirely, it may impress its likeness on it. Now it is clear that the active principle which is reason, cannot entirely overcome the appetitive power in one act: because the appetitive power is inclined variously, and to many things; while the reason judges in a single act, what should be willed in regard to various aspects and circumstances. Wherefore the appetitive power is not thereby entirely overcome, so as to be inclined like nature to the same thing, in the majority of cases; which inclination belongs to the habit of virtue. Therefore a habit of virtue cannot be caused by one act, but only by many.

But in the apprehensive powers, we must observe that there are two passive principles: one is the "possible" [*See ad 2] intellect itself; the other is the intellect which Aristotle (De Anima iii, text. 20) calls "passive," and is the "particular reason," that is the cogitative power, with memory and imagination. With regard then to the former passive principle, it is possible for a certain active principle to entirely overcome, by one act, the power of its passive principle: thus one self-evident proposition convinces the intellect, so that it gives a firm assent to the conclusion, but a probable proposition cannot do this. Wherefore a habit of opinion needs to be caused by many acts of the reason, even on the part of the "possible" intellect: whereas a habit of science can be caused by a single act of the reason, so far as the "possible" intellect is concerned. But with regard to the lower apprehensive powers, the same acts need to be repeated many times for anything to be firmly impressed on the memory. And so the Philosopher says (De Memor. et Remin. 1) that "meditation strengthens memory." Bodily habits, however, can be caused by one act, if the active principle is of great power: sometimes, for instance, a strong dose of medicine restores health at once.

Hence the solutions to the objections are clear.

Article 4: Whether any habits are infused in man by God?

it is written (Ecclus. 15:5): "God filled him with the spirit of wisdom and understanding." Now wisdom and understanding are habits. Therefore some habits are infused into man by God.

Some habits are infused by God into man, for two reasons.

The first reason is because there are some habits by which man is disposed to an end which exceeds the proportion of human nature, namely, the ultimate and perfect happiness of man, as stated above (). And since habits need to be in proportion with that to which man is disposed by them, therefore is it necessary that those habits, which dispose to this end, exceed the proportion of human nature. Wherefore such habits can never be in man except by Divine infusion, as is the case with all gratuitous virtues.

The other reason is, because God can produce the effects of second causes, without these second causes, as we have said in the . Just as, therefore, sometimes, in order to show His power, He causes health, without its natural cause, but which nature could have caused, so also, at times, for the manifestation of His power, He infuses into man even those habits which can be caused by a natural power. Thus He gave to the apostles the science of the Scriptures and of all tongues, which men can acquire by study or by custom, but not so perfectly.