Q: Whether the Acts of the External Members Are Commanded?

A: On the contrary,
Augustine says (Confess. viii, 9): "The mind commands a movement of the hand, and so ready is the hand to obey, that scarcely can one discern obedience from command."

I answer that,
The members of the body are organs of the soul's powers. Consequently according as the powers of the soul stand in respect of obedience to reason, so do the members of the body stand in respect thereof. Since then the sensitive powers are subject to the command of reason, whereas the natural powers are not; therefore all movements of members, that are moved by the sensitive powers, are subject to the command of reason; whereas those movements of members, that arise from the natural powers, are not subject to the command of reason.

Reply Obj. 1: The members do not move themselves, but are moved through the powers of the soul; of which powers, some are in closer contact with the reason than are the powers of the vegetal soul.

Reply Obj. 2: In things pertaining to intellect and will, that which is according to nature stands first, whence all other things are derived: thus from the knowledge of principles that are naturally known, is derived knowledge of the conclusions; and from volition of the end naturally desired, is derived the choice of the means. So also in bodily movements the principle is according to nature. Now the principle of bodily movements begins with the movement of the heart. Consequently the movement of the heart is according to nature, and not according to the will: for like a proper accident, it results from life, which follows from the union of soul and body. Thus the movement of heavy and light things results from their substantial form: for which reason they are said to be moved by their generator, as the Philosopher states (Phys. viii, 4). Wherefore this movement is called "vital." For which reason Gregory of Nyssa (Nemesius, De Nat. Hom. xxii) says that, just as the movement of generation and nutrition does not obey reason, so neither does the pulse which is a vital movement. By the pulse he means the movement of the heart which is indicated by the pulse veins.

Reply Obj. 3: As Augustine says (De Civ. Dei xiv, 17, 20) it is in punishment of sin that the movement of these members does not obey reason: in this sense, that the soul is punished for its rebellion against God, by the insubmission of that member whereby original sin is transmitted to posterity.

But because, as we shall state later on, the effect of the sin of our first parent was that his nature was left to itself, through the withdrawal of the supernatural gift which God had bestowed on man, we must consider the natural cause of this particular member's insubmission to reason. This is stated by Aristotle (De Causis Mot. Animal.) who says that "the movements of the heart and of the organs of generation are involuntary," and that the reason of this is as follows. These members are stirred at the occasion of some apprehension; in so far as the intellect and imagination represent such things as arouse the passions of the soul, of which passions these movements are a consequence. But they are not moved at the command of the reason or intellect, because these movements are conditioned by a certain natural change of heat and cold, which change is not subject to the command of reason. This is the case with these two organs in particular, because each is as it were a separate animal being, in so far as it is a principle of life; and the principle is virtually the whole. For the heart is the principle of the senses; and from the organ of generation proceeds the seminal virtue, which is virtually the entire animal. Consequently they have their proper movements naturally: because principles must needs be natural, as stated above (Reply Obj. 2).

QUESTION 18

OF THE GOOD AND EVIL OF HUMAN ACTS, IN GENERAL (In Eleven Articles)

We must now consider the good and evil of human acts. First, how a human act is good or evil; secondly, what results from the good or evil of a human act, as merit or demerit, sin and guilt.

Under the first head there will be a threefold consideration: the first will be of the good and evil of human acts, in general; the second, of the good and evil of internal acts; the third, of the good and evil of external acts.

Concerning the first there are eleven points of inquiry:

(1) Whether every human action is good, or are there evil actions?

(2) Whether the good or evil of a human action is derived from its object?

(3) Whether it is derived from a circumstance?

(4) Whether it is derived from the end?

(5) Whether a human action is good or evil in its species?

(6) Whether an action has the species of good or evil from its end?

(7) Whether the species derived from the end is contained under the species derived from the object, as under its genus, or conversely?

(8) Whether any action is indifferent in its species?

(9) Whether an individual action can be indifferent?

(10) Whether a circumstance places a moral action in the species of good or evil?

(11) Whether every circumstance that makes an action better or worse, places the moral action in the species of good or evil?