Читать книгу Summa Theologica, Part I-II (Pars Prima Secundae) - Thomas Aquinas - Страница 23

We must now consider the acts commanded by the will; under which head there are nine points of inquiry:

(1) Whether command is an act of the will or of the reason?

(2) Whether command belongs to irrational animals?

(3) Of the order between command and use;

(4) Whether command and the commanded act are one act or distinct?

(5) Whether the act of the will is commanded?

(6) Whether the act of the reason is commanded?

(7) Whether the act of the sensitive appetite is commanded?

(8) Whether the act of the vegetal soul is commanded?

(9) Whether the acts of the external members are commanded? ________________________

FIRST ARTICLE [I-II, Q. 17, Art. 1]

Whether Command Is an Act of the Reason or of the Will?

Objection 1: It would seem that command is not an act of the reason but of the will. For command is a kind of motion; because Avicenna says that there are four ways of moving, "by perfecting, by disposing, by commanding, and by counselling." But it belongs to the will to move all the other powers of the soul, as stated above (Q. 9, A. 1). Therefore command is an act of the will.

Obj. 2: Further, just as to be commanded belongs to that which is subject, so, seemingly, to command belongs to that which is most free. But the root of liberty is especially in the will. Therefore to command belongs to the will.

Obj. 3: Further, command is followed at once by act. But the act of the reason is not followed at once by act: for he who judges that a thing should be done, does not do it at once. Therefore command is not an act of the reason, but of the will.

On the contrary, Gregory of Nyssa [*Nemesius, De Nat. Hom. xvi.] and the Philosopher (Ethic. i, 13) say that "the appetite obeys reason." Therefore command is an act of the reason.

I answer that, Command is an act of the reason presupposing, however, an act of the will. In proof of this, we must take note that, since the acts of the reason and of the will can be brought to bear on one another, in so far as the reason reasons about willing, and the will wills to reason, the result is that the act of the reason precedes the act of the will, and conversely. And since the power of the preceding act continues in the act that follows, it happens sometimes that there is an act of the will in so far as it retains in itself something of an act of the reason, as we have stated in reference to use and choice; and conversely, that there is an act of the reason in so far as it retains in itself something of an act of the will.

Now, command is essentially indeed an act of the reason: for the commander orders the one commanded to do something, by way of intimation or declaration; and to order thus by intimating or declaring is an act of the reason. Now the reason can intimate or declare something in two ways. First, absolutely: and this intimation is expressed by a verb in the indicative mood, as when one person says to another: "This is what you should do." Sometimes, however, the reason intimates something to a man by moving him thereto; and this intimation is expressed by a verb in the imperative mood; as when it is said to someone: "Do this." Now the first mover, among the powers of the soul, to the doing of an act is the will, as stated above (Q. 9, A. 1). Since therefore the second mover does not move, save in virtue of the first mover, it follows that the very fact that the reason moves by commanding, is due to the power of the will. Consequently it follows that command is an act of the reason, presupposing an act of the will, in virtue of which the reason, by its command, moves (the power) to the execution of the act.

Reply Obj. 1: To command is to move, not anyhow, but by intimating and declaring to another; and this is an act of the reason.

Reply Obj. 2: The root of liberty is the will as the subject thereof; but it is the reason as its cause. For the will can tend freely towards various objects, precisely because the reason can have various perceptions of good. Hence philosophers define the free-will as being "a free judgment arising from reason," implying that reason is the root of liberty.

Reply Obj. 3: This argument proves that command is an act of reason not absolutely, but with a kind of motion as stated above. ________________________

SECOND ARTICLE [I-II, Q. 17, Art. 2]

Whether Command Belongs to Irrational Animals?

Objection 1: It would seem that command belongs to irrational animals. Because, according to Avicenna, "the power that commands movement is the appetite; and the power that executes movement is in the muscles and nerves." But both powers are in irrational animals. Therefore command is to be found in irrational animals.

Obj. 2: Further, the condition of a slave is that of one who receives commands. But the body is compared to the soul as a slave to his master, as the Philosopher says (Polit. i, 2). Therefore the body is commanded by the soul, even in irrational animals, since they are composed of soul and body.

Obj. 3: Further, by commanding, man has an impulse towards an action.

But impulse to action is to be found in irrational animals, as

Damascene says (De Fide Orth. ii, 22). Therefore command is to be

found in irrational animals.

On the contrary, Command is an act of reason, as stated above (A. 1). But in irrational animals there is no reason. Neither, therefore, is there command.

I answer that, To command is nothing else than to direct someone to do something, by a certain motion of intimation. Now to direct is the proper act of reason. Wherefore it is impossible that irrational animals should command in any way, since they are devoid of reason.

Reply Obj. 1: The appetitive power is said to command movement, in so far as it moves the commanding reason. But this is only in man. In irrational animals the appetitive power is not, properly speaking, a commanding faculty, unless command be taken loosely for motion.

Reply Obj. 2: The body of the irrational animal is competent to obey; but its soul is not competent to command, because it is not competent to direct. Consequently there is no ratio there of commander and commanded; but only of mover and moved.

Reply Obj. 3: Impulse to action is in irrational animals otherwise than in man. For the impulse of man to action arises from the directing reason; wherefore his impulse is one of command. On the other hand, the impulse of the irrational animal arises from natural instinct; because as soon as they apprehend the fitting or the unfitting, their appetite is moved naturally to pursue or to avoid. Wherefore they are directed by another to act; and they themselves do not direct themselves to act. Consequently in them is impulse but not command. ________________________

THIRD ARTICLE [I-II, Q. 17, Art. 3]

Whether Use Precedes Command?

Objection 1: It would seem that use precedes command. For command is an act of the reason presupposing an act of the will, as stated above (A. 1). But, as we have already shown (Q. 16, A. 1), use is an act of the will. Therefore use precedes command.

Obj. 2: Further, command is one of those things that are ordained to the end. But use is of those things that are ordained to the end. Therefore it seems that use precedes command.

Obj. 3: Further, every act of a power moved by the will is called use; because the will uses the other powers, as stated above (Q. 16, A. 1). But command is an act of the reason as moved by the will, as stated above (A. 1). Therefore command is a kind of use. Now the common precedes the proper. Therefore use precedes command.

On the contrary, Damascene says (De Fide Orth. ii, 22) that impulse to action precedes use. But impulse to operation is given by command. Therefore command precedes use.

I answer that, use of that which is directed to the end, in so far as it is in the reason referring this to the end, precedes choice, as stated above (Q. 16, A. 4). Wherefore still more does it precede command. On the other hand, use of that which is directed to the end, in so far as it is subject to the executive power, follows command; because use in the user is united to the act of the thing used; for one does not use a stick before doing something with the stick. But command is not simultaneous with the act of the thing to which the command is given: for it naturally precedes its fulfilment, sometimes, indeed, by priority of time. Consequently it is evident that command precedes use.

Reply Obj. 1: Not every act of the will precedes this act of the reason which is command; but an act of the will precedes, viz. choice; and an act of the will follows, viz. use. Because after counsel's decision, which is reason's judgment, the will chooses; and after choice, the reason commands that power which has to do what was chosen; and then, last of all, someone's will begins to use, by executing the command of reason; sometimes it is another's will, when one commands another; sometimes the will of the one that commands, when he commands himself to do something.

Reply Obj. 2: Just as act ranks before power, so does the object rank before the act. Now the object of use is that which is directed to the end. Consequently, from the fact that command [itself is directed to the end, it may be concluded that command] precedes, rather than that it follows use.

Reply Obj. 3: Just as the act of the will in using the reason for the purpose of command, precedes the command; so also we may say that this act whereby the will uses the reason, is preceded by a command of reason; since the acts of these powers react on one another. ________________________

FOURTH ARTICLE [I-II, Q. 17, Art. 4]

Whether Command and the Commanded Act Are One Act, or Distinct?

Objection 1: It would seem that the commanded act is not one with the command itself. For the acts of different powers are themselves distinct. But the commanded act belongs to one power, and the command to another; since one is the power that commands, and the other is the power that receives the command. Therefore the commanded act is not one with the command.

Obj. 2: Further, whatever things can be separate from one another, are distinct: for nothing is severed from itself. But sometimes the commanded act is separate from the command: for sometimes the command is given, and the commanded act follows not. Therefore command is a distinct act from the act commanded.

Obj. 3: Further, whatever things are related to one another as precedent and consequent, are distinct. But command naturally precedes the commanded act. Therefore they are distinct.

On the contrary, The Philosopher says (Topic. iii, 2) that "where one thing is by reason of another, there is but one." But there is no commanded act unless by reason of the command. Therefore they are one.

I answer that, Nothing prevents certain things being distinct in one respect, and one in another respect. Indeed, every multitude is one in some respect, as Dionysius says (Div. Nom. xiii). But a difference is to be observed in this, that some are simply many, and one in a particular aspect: while with others it is the reverse. Now "one" is predicated in the same way as "being." And substance is being simply, whereas accident or being "of reason" is a being only in a certain respect. Wherefore those things that are one in substance are one simply, though many in a certain respect. Thus, in the genus substance, the whole composed of its integral or essential parts, is one simply: because the whole is being and substance simply, and the parts are being and substances in the whole. But those things which are distinct in substance, and one according to an accident, are distinct simply, and one in a certain respect: thus many men are one people, and many stones are one heap; which is unity of composition or order. In like manner also many individuals that are one in genus or species are many simply, and one in a certain respect: since to be one in genus or species is to be one according to the consideration of the reason.

Now just as in the genus of natural things, a whole is composed of matter and form (e.g. man, who is one natural being, though he has many parts, is composed of soul and body); so, in human acts, the act of a lower power is in the position of matter in regard to the act of a higher power, in so far as the lower power acts in virtue of the higher power moving it: for thus also the act of the first mover is as the form in regard to the act of its instrument. Hence it is evident that command and the commanded act are one human act, just as a whole is one, yet in its parts, many.

Reply Obj. 1: If the distinct powers are not ordained to one another, their acts are diverse simply. But when one power is the mover of the other, then their acts are, in a way, one: since "the act of the mover and the act of the thing moved are one act" (Phys. iii, 3).

Reply Obj. 2: The fact that command and the commanded act can be separated from one another shows that they are different parts. Because the parts of a man can be separated from one another, and yet they form one whole.

Reply Obj. 3: In those things that are many in parts, but one as a whole, nothing hinders one part from preceding another. Thus the soul, in a way, precedes the body; and the heart, the other members. ________________________

FIFTH ARTICLE [I-II, Q. 17, Art. 5]

Whether the Act of the Will Is Commanded?

Objection 1: It would seem that the act of the will is not commanded.

For Augustine says (Confess. viii, 9): "The mind commands the mind to

will, and yet it does not." But to will is the act of the will.

Therefore the act of the will is not commanded.

Obj. 2: Further, to receive a command belongs to one who can understand the command. But the will cannot understand the command; for the will differs from the intellect, to which it belongs to understand. Therefore the act of the will is not commanded.

Obj. 3: Further, if one act of the will is commanded, for the same reason all are commanded. But if all the acts of the will are commanded, we must needs proceed to infinity; because the act of the will precedes the act of reason commanding, as stated above (A. 1); for if that act of the will be also commanded, this command will be preceded by another act of the reason, and so on to infinity. But to proceed to infinity is not possible. Therefore the act of the will is not commanded.

On the contrary, Whatever is in our power, is subject to our command. But the acts of the will, most of all, are in our power; since all our acts are said to be in our power, in so far as they are voluntary. Therefore the acts of the will are commanded by us.

I answer that, As stated above (A. 1), command is nothing else than the act of the reason directing, with a certain motion, something to act. Now it is evident that the reason can direct the act of the will: for just as it can judge it to be good to will something, so it can direct by commanding man to will. From this it is evident that an act of the will can be commanded.

Reply Obj. 1: As Augustine says (Confess. viii, 9) when the mind commands itself perfectly to will, then already it wills: but that sometimes it commands and wills not, is due to the fact that it commands imperfectly. Now imperfect command arises from the fact that the reason is moved by opposite motives to command or not to command: wherefore it fluctuates between the two, and fails to command perfectly.

Reply Obj. 2: Just as each of the members of the body works not for itself alone but for the whole body; thus it is for the whole body that the eye sees; so is it with the powers of the soul. For the intellect understands, not for itself alone, but for all the powers; and the will wills not only for itself, but for all the powers too. Wherefore man, in so far as he is endowed with intellect and will, commands the act of the will for himself.

Reply Obj. 3: Since command is an act of reason, that act is commanded which is subject to reason. Now the first act of the will is not due to the direction of the reason but to the instigation of nature, or of a higher cause, as stated above (Q. 9, A. 4). Therefore there is no need to proceed to infinity. ________________________

SIXTH ARTICLE [I-II, Q. 17, Art. 6]

Whether the Act of the Reason Is Commanded?

Objection 1: It would seem that the act of the reason cannot be commanded. For it seems impossible for a thing to command itself. But it is the reason that commands, as stated above (A. 1). Therefore the act of the reason is not commanded.

Obj. 2: Further, that which is essential is different from that which is by participation. But the power whose act is commanded by reason, is rational by participation, as stated in Ethic. i, 13. Therefore the act of that power, which is essentially rational, is not commanded.

Obj. 3: Further, that act is commanded, which is in our power. But to know and judge the truth, which is the act of reason, is not always in our power. Therefore the act of the reason cannot be commanded.

On the contrary, That which we do of our free-will, can be done by our command. But the acts of the reason are accomplished through the free-will: for Damascene says (De Fide Orth. ii, 22) that "by his free-will man inquires, considers, judges, approves." Therefore the acts of the reason can be commanded.

I answer that, Since the reason reacts on itself, just as it directs the acts of other powers, so can it direct its own act. Consequently its act can be commanded.

But we must take note that the act of the reason may be considered in two ways. First, as to the exercise of the act. And considered thus, the act of the reason can always be commanded: as when one is told to be attentive, and to use one's reason. Secondly, as to the object; in respect of which two acts of the reason have to be noticed. One is the act whereby it apprehends the truth about something. This act is not in our power: because it happens in virtue of a natural or supernatural light. Consequently in this respect, the act of the reason is not in our power, and cannot be commanded. The other act of the reason is that whereby it assents to what it apprehends. If, therefore, that which the reason apprehends is such that it naturally assents thereto, e.g. the first principles, it is not in our power to assent or dissent to the like: assent follows naturally, and consequently, properly speaking, is not subject to our command. But some things which are apprehended do not convince the intellect to such an extent as not to leave it free to assent or dissent, or at least suspend its assent or dissent, on account of some cause or other; and in such things assent or dissent is in our power, and is subject to our command.

Reply Obj. 1: Reason commands itself, just as the will moves itself, as stated above (Q. 9, A. 3), that is to say, in so far as each power reacts on its own acts, and from one thing tends to another.

Reply Obj. 2: On account of the diversity of objects subject to the act of the reason, nothing prevents the reason from participating in itself: thus the knowledge of principles is participated in the knowledge of the conclusions.

The reply to the third object is evident from what has been said. ________________________

SEVENTH ARTICLE [I-II, Q. 17, Art. 7]

Whether the Act of the Sensitive Appetite Is Commanded?

Objection 1: It would seem that the act of the sensitive appetite is not commanded. For the Apostle says (Rom. 7:15): "For I do not that good which I will": and a gloss explains this by saying that man lusts, although he wills not to lust. But to lust is an act of the sensitive appetite. Therefore the act of the sensitive appetite is not subject to our command.

Obj. 2: Further, corporeal matter obeys God alone, to the effect of formal transmutation, as was shown in the First Part (Q. 65, A. 4; Q. 91, A. 2; Q. 110, A. 2). But the act of the sensitive appetite is accompanied by a formal transmutation of the body, consisting in heat or cold. Therefore the act of the sensitive appetite is not subject to man's command.

Obj. 3: Further, the proper motive principle of the sensitive appetite is something apprehended by sense or imagination. But it is not always in our power to apprehend something by sense or imagination. Therefore the act of the sensitive appetite is not subject to our command.

On the contrary, Gregory of Nyssa [*Nemesius, De Nat. Hom. xvi.] says: "That which obeys reason is twofold, the concupiscible and the irascible," which belong to the sensitive appetite. Therefore the act of the sensitive appetite is subject to the command of reason.

I answer that, An act is subject to our command, in so far as it is in our power, as stated above (A. 5). Consequently in order to understand in what manner the act of the sensitive appetite is subject to the command of reason, we must consider in what manner it is in our power. Now it must be observed that the sensitive appetite differs from the intellective appetite, which is called the will, in the fact that the sensitive appetite is a power of a corporeal organ, whereas the will is not. Again, every act of a power that uses a corporeal organ, depends not only on a power of the soul, but also on the disposition of that corporeal organ: thus the act of vision depends on the power of sight, and on the condition of the eye, which condition is a help or a hindrance to that act. Consequently the act of the sensitive appetite depends not only on the appetitive power, but also on the disposition of the body.

Now whatever part the power of the soul takes in the act, follows apprehension. And the apprehension of the imagination, being a particular apprehension, is regulated by the apprehension of reason, which is universal; just as a particular active power is regulated by a universal active power. Consequently in this respect the act of the sensitive appetite is subject to the command of reason. On the other hand, condition or disposition of the body is not subject to the command of reason: and consequently in this respect, the movement of the sensitive appetite is hindered from being wholly subject to the command of reason.

Moreover it happens sometimes that the movement of the sensitive appetite is aroused suddenly in consequence of an apprehension of the imagination of sense. And then such movement occurs without the command of reason: although reason could have prevented it, had it foreseen. Hence the Philosopher says (Polit. i, 2) that the reason governs the irascible and concupiscible not by a "despotic supremacy," which is that of a master over his slave; but by a "politic and royal supremacy," whereby the free are governed, who are not wholly subject to command.

Reply Obj. 1: That man lusts, although he wills not to lust, is due to a disposition of the body, whereby the sensitive appetite is hindered from perfect compliance with the command of reason. Hence the Apostle adds (Rom. 7:15): "I see another law in my members, fighting against the law of my mind." This may also happen through a sudden movement of concupiscence, as stated above.

Reply Obj. 2: The condition of the body stands in a twofold relation to the act of the sensitive appetite. First, as preceding it: thus a man may be disposed in one way or another, in respect of his body, to this or that passion. Secondly, as consequent to it: thus a man becomes heated through anger. Now the condition that precedes, is not subject to the command of reason: since it is due either to nature, or to some previous movement, which cannot cease at once. But the condition that is consequent, follows the command of reason: since it results from the local movement of the heart, which has various movements according to the various acts of the sensitive appetite.

Reply Obj. 3: Since the external sensible is necessary for the apprehension of the senses, it is not in our power to apprehend anything by the senses, unless the sensible be present; which presence of the sensible is not always in our power. For it is then that man can use his senses if he will so to do; unless there be some obstacle on the part of the organ. On the other hand, the apprehension of the imagination is subject to the ordering of reason, in proportion to the strength or weakness of the imaginative power. For that man is unable to imagine the things that reason considers, is either because they cannot be imagined, such as incorporeal things; or because of the weakness of the imaginative power, due to some organic indisposition. ________________________

EIGHTH ARTICLE [I-II, Q. 17, Art. 8]

Whether the Act of the Vegetal Soul Is Commanded?

Objection 1: It would seem that the acts of the vegetal soul are subject to the command of reason. For the sensitive powers are of higher rank than the vegetal powers. But the powers of the sensitive soul are subject to the command of reason. Much more, therefore, are the powers of the vegetal soul.

Obj. 2: Further, man is called a "little world" [*Aristotle, Phys. viii. 2], because the soul is in the body, as God is in the world. But God is in the world in such a way, that everything in the world obeys His command. Therefore all that is in man, even the powers of the vegetal soul, obey the command of reason.

Obj. 3: Further, praise and blame are awarded only to such acts as are subject to the command of reason. But in the acts of the nutritive and generative power, there is room for praise and blame, virtue and vice: as in the case of gluttony and lust, and their contrary virtues. Therefore the acts of these powers are subject to the command of reason.

On the contrary, Gregory of Nyssa [*Nemesius, De Nat. Hom. xxii.] says that "the nutritive and generative power is one over which the reason has no control."

I answer that, Some acts proceed from the natural appetite, others from the animal, or from the intellectual appetite: for every agent desires an end in some way. Now the natural appetite does not follow from some apprehension, as [d]o the animal and the intellectual appetite. But the reason commands by way of apprehensive power. Wherefore those acts that proceed from the intellective or the animal appetite, can be commanded by reason: but not those acts that proceed from the natural appetite. And such are the acts of the vegetal soul; wherefore Gregory of Nyssa (Nemesius, De Nat. Hom. xxii) says "that generation and nutrition belong to what are called natural powers." Consequently the acts of the vegetal soul are not subject to the command of reason.

Reply Obj. 1: The more immaterial an act is, the more noble it is, and the more is it subject to the command of reason. Hence the very fact that the acts of the vegetal soul do not obey reason, shows that they rank lowest.

Reply Obj. 2: The comparison holds in a certain respect: because, to wit, as God moves the world, so the soul moves the body. But it does not hold in every respect: for the soul did not create the body out of nothing, as God created the world; for which reason the world is wholly subject to His command.

Reply Obj. 3: Virtue and vice, praise and blame do not affect the acts themselves of the nutritive and generative power, i.e. digestion, and formation of the human body; but they affect the acts of the sensitive part, that are ordained to the acts of generation and nutrition; for example the desire for pleasure in the act of taking food or in the act of generation, and the right or wrong use thereof. ________________________

NINTH ARTICLE [I-II, Q. 17, Art. 9]

Whether the Acts of the External Members Are Commanded?

Objection 1: It would seem that the members of the body do not obey reason as to their acts. For it is evident that the members of the body are more distant from the reason, than the powers of the vegetal soul. But the powers of the vegetal soul do not obey reason, as stated above (A. 8). Therefore much less do the members of the body obey.

Obj. 2: Further, the heart is the principle of animal movement. But the movement of the heart is not subject to the command of reason: for Gregory of Nyssa [*Nemesius, De Nat. Hom. xxii.] says that "the pulse is not controlled by reason." Therefore the movement of the bodily members is not subject to the command of reason.

Obj. 3: Further, Augustine says (De Civ. Dei xiv, 16) that "the movement of the genital members is sometimes inopportune and not desired; sometimes when sought it fails, and whereas the heart is warm with desire, the body remains cold." Therefore the movements of the members are not obedient to reason.

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).