Chapter 89 — Solution of the foregoing arguments

For the easier solution of the foregoing arguments, we must first of all set down certain points in order to explain the order and process of the generation of man, as well as of animals in general.

In the first place, then, it must be observed that the opinion of those is false who say that the vital operations that appear in the embryo before its ultimate completion, do not proceed from a soul or soul’s power, existing therein, but from the soul of the mother. For if this were true, the embryo will no longer be an animal, since every animal consists of soul and body. Moreover, vital operations do not proceed from an extrinsic active principle, but from an internal force; it is in this that inanimate things differ from the living, to which it properly belongs to move themselves. That which is nourished assimilates nourishment: therefore, in the subject nourished there must be an active nutritive power, since the agent produces its like. And much more evident is this in the operation of the senses: because to see and to hear are competent to a person through some faculty existing in him and not in another. Therefore, if the embryo is observed to be nourished and even to sense before its final development, that cannot be ascribed to the soul of the mother.

And yet it cannot be said that the soul is in the semen from the very beginning as to its complete essence, and that the operations of the soul are not apparent on account of the lack of organs. For, since the soul is united to the body as its form, it is not united to a body other than one of which it is properly the act. Now the soul is the act of an organic body. (Aristotle, On the Soul 2.1, 412b5.) Consequently, the soul is not actually in the semen before the organization of the body, but only potentially or virtually. And thus Aristotle says that seed and fruit are potentially living as long as they put aside, i.e., are without, the soul; yet the thing of which the soul is the act is potentially living, but is not without a soul. (Aristotle, On the Soul 2.1, 412b25–413a3.)

It would also follow, if the soul were in the semen from the beginning, that the generation of an animal would be by mere severance, as happens in annulose animals, where two are made from one. For if the semen were animated as soon as severed, it would at once have a substantial form. Now every substantial generation precedes, and does not follow, the substantial form; if any changes follow the substantial form, they are directed not to the being, but to the well-being of the thing generated. Accordingly, the generation of the animal would be completed in the mere severance of the semen: and all subsequent changes would have nothing to do with generation.

Even more absurd would this be if applied to the rational soul: both because it cannot possibly be divided according to the division of the body, so that it be possible for it to be in the semen after severance, and because it would follow that whenever pollution occurs without conception taking place, rational souls would nevertheless be multiplied.

Nor can it be asserted, as some say, that although from the moment of severance the soul is not in the semen actually but virtually, on account of the lack of organs, yet this very power of the semen (which is a body capable of receiving organs though it has them not actually) is proportionately a potential but not an actual soul to the semen. And since the life of a plant requires fewer organs than the life of an animal, this same power of the semen becomes a vegetative soul when the semen is first sufficiently prepared for vegetative life. Then, when the organs have been yet more perfected and multiplied, the same power advances to the state of a sensitive soul. Further still, the form of the organs being perfected, the same soul becomes rational—not indeed by the action of this seminal power, but by the action of an external agent, for which reason they imagine Aristotle to have said that the intellect is from without. (Aristotle, On the Generation of Animals 2.3.) For, according to this opinion, it would follow that the same identical power is at one time a purely vegetative soul, and afterwards a sensitive soul, so that the substantial form itself would be perfected more and more by stages. It would also follow that the substantial form would be brought from potency to act not at once, but by degrees. And again, that generation, like alteration, is a continuous movement. All of which things are impossible in nature.

A conclusion still more inadmissible would follow, namely, that the rational soul is mortal. For nothing that accrues as a form to that which is corruptible makes it naturally incorruptible, or else a corruptible thing would be changed into an incorruptible one, which is impossible, since they differ in genus, as stated in 10 Metaphysics. (Aristotle, Metaphysics 10.10, 1058b27–28.) Now, since in the aforesaid process the substance of the sensitive soul is stated to be generated accidentally by the generated body, it must be corruptible at the corruption of the body. If, therefore, the same soul becomes rational by a light introduced within it, which light is related to it as a form (for the sensitive is potentially intellective), it necessarily follows that the rational soul perishes when the body perishes. And this is impossible as we proved above, (Ch. 79.) and as the Catholic faith teaches.

Therefore, the selfsame power which is severed together with the semen and is called the formative power is not the soul, nor does it become the soul in the process of generation: but, since it is based, as on its proper subject, on the (vital) spirit contained in the frothy semen, it causes the formation of the body insofar as it operates by power of the father’s soul, to whom generation is ascribed as the principal agent, and not by power of the soul of the person conceived, even after the soul is in that person: for the subject conceived does not generate itself, but is generated by the father.

This is clear to anyone who considers each power of the soul separately. For it cannot be ascribed to the soul of the embryo by reason of the generative power, not only because the generative power does not exercise its operation until the work of the nutritive and augmentative powers, which are its auxiliaries, is completed (since to generate belongs to that which is perfect), but also because the work of the generative power is directed not to the perfection of the individual, but to the preservation of the species.

Nor again can it be ascribed to the nutritive power, whose work is to assimilate nourishment to the subject nourished, which is not apparent here, for in the process of formation the nourishment is not assimilated to something already existing, but is advanced to a more perfect form and more approaching to a likeness to the father. Likewise, neither can it be ascribed to the augmentative power, for it belongs to this power to cause a change not of form, but of quantity. As to the sensitive and intellective part, it is clear that it has no operation appropriate to such a formation.

It remains, then, that the formation of the body, especially as regards the foremost and principal parts, is not from the form of the subject generated, nor from a formative power acting by power of that form, but from (a formative power) acting by power of the father’s generative soul, whose work is to produce the specific like of the generator.

Accordingly, this formative power remains the same in the aforesaid spirit from the beginning of the formation until the end. Yet the species of the subject formed does not remain the same, because at first it has the form of semen, afterwards of blood, and so onwards until it arrives at its final complement. For although the generation of simple bodies does not proceed in order (since each of them has an immediate form of prime matter), in the generation of other bodies there must be an order in the generations because of the many intermediate forms between the first elemental form and the final form which is the term of generation. And therefore there are a number of generations and corruptions following one another.

Nor is it unreasonable if one of the intermediates be generated and then at once interrupted, because the intermediate stages do not have a complete species but are on the way to a species: hence they are generated not so that they may remain, but that the final term of generation may be reached through them. Nor need we wonder if the transmutation of generation is not continuous throughout, and that there are many intermediate generations, for this also happens in alteration and growth, since neither alteration nor growth is continuous throughout, but only local movement is truly continuous, as we find proved in Physics 8. (Aristotle, Physics 8.7, 261a28–b26.)

Accordingly, the more noble a form is and the further removed it is from the elemental form, the more numerous must be the intermediate forms through which the ultimate form is reached by degrees, and consequently the more numerous will be the intermediate generations. Therefore, in the generation of an animal or a man in which the form is most perfect, there are many intermediate forms and generations, and consequently corruptions, since the generation of one is the corruption of another. (Aristotle, Physics 3.8, 208a8–10.) Therefore, the vegetative soul, which comes first when the embryo lives the life of a plant, is corrupted, and is succeeded by a more perfect soul which is both nutritive and sensitive, and then the embryo lives an animal life. When this is corrupted, it is succeeded by the rational soul introduced from without, although the preceding souls were produced by the power in the semen.

These being seen, it is easy to answer the objections. (Preceding chapter.)

For in reply to the first objection, where it is stated that the sensitive soul must have the same manner of origin in man and in irrational animals, because “animal” is predicated of both univocally, we say that this is not necessary. For although the sensitive souls in man and dumb animals agree generically, they differ specifically, like the things of which they are the forms. For just as the animal that is a man differs specifically from other animals in the point of being rational, so the sensitive soul of man differs specifically from the sensitive soul of a dumb animal in this: it is also intellective. Therefore, the sensitive soul in the dumb animal has no more than the sensitive faculty: and consequently neither its being nor its operation is raised above the body. And so it must be generated together with the body, and perish when the body perishes. On the other hand, the sensitive soul in a man, through having an intellective power in addition to the sensitive nature (from which it follows that it is raised above the body both in being and in operation), is neither generated through the generation of the body, nor perishes through the body’s corruption. Hence the different manner of origin in the aforesaid souls is not on the part of the sensitive faculty from which the generic nature is taken, but on the part of the intellective faculty, from which the specific difference is derived. Therefore, we can conclude a difference not of genus but only of species.

When it is objected in the second place that the thing conceived is an animal before a man, this does not prove that the rational soul is transmitted together with the semen. For the sensitive soul by which it was an animal does not remain, but is succeeded by a soul that is both sensitive and intellective, by which it is both animal and man at the same time, as explained above.

The statement in the third objection—that the actions of different agents do not terminate in one thing made—must be understood as referring to different agents of which one is not ordered to the other. For if they be ordered the one to the other, they must have one effect, for the first active cause acts on the effect of the secondary active cause more intimately than does the secondary cause. Hence we find that an effect produced by a principal agent through an instrument is more properly ascribed to the principal agent than to the instrument. Now it happens sometimes that the action of the principal agent attains to something in the effect produced, to which the action of the instrument does not attain: thus the vegetative power produces the species of flesh, which the heat of fire that is its instrument cannot produce, although it acts dispositively to it by dissolving and consuming. Since, then, every active force of nature is compared to God as an instrument is compared to the first and principal agent, nothing hinders the action of nature from terminating in a part of man and not in the whole (which is the effect of God’s action) in one and the same subject generated which is a man. Accordingly, the human body is fashioned at the same time both by the power of God as the principal and first agent, and by the power of the semen as secondary agent, but God’s action produces the human soul, which the seminal power cannot produce, but to which it disposes.

Hence the reply to the fourth objection is clear. For thus a man begets his like in species insofar as the seminal power in him operates dispositively towards the ultimate form from which man derives his species.

That God should cooperate with adulterers in the action of nature involves no contradiction. For it is not the nature but the will that is evil in adulterers: the action which proceeds from their seminal virtue is natural and not voluntary. Therefore, it is not unreasonable that God cooperate in their action by giving it its ultimate perfection.

As to the sixth objection, it is clear that the conclusion does not necessarily follow. For even if we grant that man’s body is fashioned before the soul is created, or vice versa, it does not follow that the selfsame man precedes himself, since a man is not his body nor his soul. But it follows that some part of him precedes the other. In this there is nothing unreasonable, because matter precedes form in point of time. (I say “matter” considered as being in potency to form, but not as actually perfected by a form, for it is thus simultaneous with the form.) Accordingly, the human body precedes the soul in point of time, considered as in potency to the soul and as not yet having a soul, but then it is human not actually, but only potentially. On the other hand, when it is human actually as being perfected by the human soul, it neither precedes nor follows the soul, but is simultaneous with it.

Nor again does it follow that the operation both of God and of nature is imperfect if the soul is not produced by the seminal virtue, but only the body, as the seventh argument inferred. For both body and soul are made by the power of God, although the fashioning of the body is from him by means of the natural power in the semen, while he produces the soul immediately. Neither does it follow that the action of the seminal power is imperfect, since it fulfils the purpose for which it is intended.

It must also be noted that the semen contains virtually whatever does not surpass a corporeal power (for instance, the grass with the stem, stalks, and so forth). Hence we cannot conclude that the part of man which surpasses the whole corporeal power is contained virtually in the semen, as the eighth argument inferred.

That the operations of the soul seem to develop in the process of human generation (according as the parts of the body develop) does not prove that the human soul and body have the same principle, as the ninth argument suggested, but it proves that the disposition of the body’s parts is necessary for the soul’s operation.

The statement of the tenth objection—that the body is conformed to the soul, and that for this reason the soul fashions a body like to itself—is partly true and partly false. For if it be understood of the soul of the begetter, the statement is true, but it is false if it be referred to the soul of the begotten. For the body is not formed by the power of the soul of the begotten, as regards the body’s foremost and principal parts, but by the power of the soul of the begetter, as we proved above. (In this chapter.) For all matter is similarly configured to its form, and yet this configuration results not from the action of the subject generated, but from the action of the generator.

As to the eleventh objection about the life of the semen at the beginning of its severance, it is clear from what has been said that it is not living except potentially. Therefore, it has a soul then not actually, but virtually. In the process of generation, it has a vegetative and a sensitive soul by the virtue of the semen, which do not remain but pass away when the rational soul takes their place.

Nor again does it follow that the soul is for the sake of the body if the fashioning of the body precedes the human soul, as the twelfth objection inferred. For one thing is for another’s sake in two ways. First, for the sake of its operation, or preservation, or any like thing consequent upon being, and such things are posterior to the thing for the sake of which they are: thus clothes are for man, and tools for the workman. Second, a thing is for another’s sake (that is, for the sake of its being): thus a thing which is for the sake of another precedes the latter in the order of time, but follows it in the order of nature. It is in this way that the body is for the sake of the soul, just as all matter is for the sake of a form. It would be otherwise if from soul and body there resulted a thing that is not one in being, as those assert who deny that the soul is the form of the body.