CHAPTER LXXXVI—That the Human Soul is not transmitted by Generation⁴⁶¹⁴⁶¹This doctrine, called traducianism, that the soul is transmitted (traducitur) from parent to offspring in the act of generation, is ascribed to Tertullian.

Where the activities of active principles suppose the concurrence of a body, the origination also of such principles supposed bodily concurrence: for a thing has existence according as it has activity: everything is active according to its being. But when active principles have their activities independent of bodily concurrence, the reverse is the case: the genesis of such principles is not by any bodily generation. Now the activity of the vegitative and sentient soul cannot be without bodily concurrence (Chapp. LVII, LXVIII): but the activity of the intellectual soul has place through no bodily organ (Chap. LXIX). Therefore the vegitative and sentient souls are generated by the generation of the body, and date their existence from the transmission of the male semen, but not the intellectual soul.⁴⁶²⁴⁶²   The force of this admission will appear in the next two chapters. Two propositions must be kept apart:—
   (a) The origin of the intellectual soul of man is synchronous with the moment of conception.
   (b) The intellectual soul of man is, as the body of man, simply a product of conception.
   St Thomas denies both these propositions. Modern Catholic theologians usually are content with denying the second only.

2. If the human soul owed its origin to the transmission of the male semen, that could be only in one of two ways. Either we must suppose that the soul is actually in the male semen, being as it were accidentally separated from the soul of the generator as the semen is separated from the body: — we see something of this sort in Annelid animals,⁴⁶³⁴⁶³   Annulosa, St Thomas calls them: they are now known as Annelidae, worms, centipedes, and the like. The cutting of an Annelid in two is not a case of reproduction. But in the lowest animal life, that of Amoebae, there is a true reproduction by ‘fissure’; as also in the propagation of plants by cuttings.
   The kindness of a medical friend suplies me with the following statement:
   “When the body of an Annelid, say an earthworm, is divided, as by the stroke of a spade, the animal does not necessarily die, does not necessarily live. The principal nerve gangia are situated in the head, and though the severed part, remote from this, so-called, central nervous system, will have no restorative power and will die, the segment containing the nerve masses — ‘brain’ — may restore or reproduce the missing opposite extremity, or a semblance of it. But, if the injury were very near the head, so that almost all the vital organs, viscera, etc., were included in the segment remote from the nerve ganglia, death would occur, not even the nerve ganglia in the head having the power to restore or reproduce an almost entirely new body, viscera, blood vessels, etc. So, while one part may live, both parts may die. It depends upon the amount and importance of the part or parts to be reproduced, or restored.” that live when cut in pieces: these creatures have one soul actually and many potentially; and when the body is divided, a soul comes to be actually in every living part: — or in another way it may be supposed that there is in the male semen a power productive of an 164intellectual soul, so that the intellectual soul may be taken to be in the said semen virtually, not actually. The first of these suppositions is impossible for two reasons. First, because the intelligent soul being the most perfect of souls and the most potent, the proper subject for it to perfect is a body having a great diversity of organs apt to respond to its manifold activities: hence the intellectual soul cannot be in the male semen cut off from the body (in semine deciso), because neither are the souls of the lower animals of the more perfect sort multiplied by cutting them in pieces (per decisionem), as is the case with Annelid animals. Secondly, because the proper and principal faculty of the intelligent soul, the intellect, not being the actualisation of any part of the body,⁴⁶⁴⁴⁶⁴As sight, for example, is the actuality (ἐντελέχεια, realisation, or full perfection) of the eye. cannot be accidentally divided with the division of the body: therefore neither can the intelligent soul. The second supposition (that the intelligent soul is virtually contained in the male semen) is also impossible. For the active power in the semen is effectual to the generation of an animal by effecting a bodily transmutation: there is no other way for a material power to take effect. But every form, which owes its being to a transmutation of matter, has being in dependence on matter: for (n. 3) every form, educed into existence by a transmutation of matter, is a form educed out of the potentiality of matter: for this is the meaning of a transmutation of matter, that something is educed into actuality out of potentiality. But an intelligent soul cannot be educed out of the potentiality of matter: for it has been shown above (Chap. LXVIII) that the intelligent soul transcends the whole power of matter, as it has an immaterial activity (Chap. LXIX). Therefore the intelligent soul is not induced into being by any transmutation of matter, and therefore not by the action of any power that is in the male semen.

5. It is ridiculous to say that any subsistent intelligence is either divided by division of the body or produced by any corporeal power. But the soul is a subsistent intelligence (Chap. LXVIII). Therefore it can neither be divided by the separation of the semen from the body, nor produced by any active power in the same.

6. If the generation of this is the cause of that coming to be, the destruction of this will be the cause of that ceasing to be. But the destruction of the body is not the cause of the human soul ceasing to be (Chap. LXXIX). Neither then is the generation of the body the cause of the soul commencing to be.