(i.) (Souls cannot, as do bodies, lose or gain parts, ever remaining identical.) The body has the faculty of making its organs grow within a definite time and in fixed proportions. From where could the soul derive them? Its function is to grow, not to cause growth, unless the principle of growth be comprehended within its material mass. If the soul that makes the body grow was herself a body, she should, on uniting with molecules of a nature similar to hers, develop a growth proportional to that of the organs. In this case, the molecules that will come to add themselves to the soul will be either animate or inanimate; if they are animate, how could they have become such, and from whom will they have received that characteristic? If they are not animate, how will they become such, and how will agreement between them and the first soul arise? How will they form but a single unity with her, and how will they agree with her? Will they not constitute a soul that will remain foreign to the former, who will not possess her requirements of knowledge? This aggregation of molecules that would thus be called soul will resemble the aggregation of molecules that form our body. She would lose parts, she would acquire new ones; she will not be identical. But if we had a soul that was not identical, memory and self-consciousness of our own faculties would be impossible.
THE SOUL IS EVERYWHERE ENTIRE; THAT IS NOT THE CASE WITH THE BODY.
(j.) (The soul, being one and simple, is everywhere entire, and has parts that are identical to the whole; this is not the case with the body.) If the soul is a body, she will have parts that are not identical with the whole, as every body is by nature divisible. If then the soul has a definite magnitude of which she cannot lose anything without ceasing to be a soul, she will by losing her parts, change her nature, as happens to every quantity. If, on losing some part of its magnitude, a body, notwithstanding, remains identical in respect to quality, it does not nevertheless become different from what it was, in respect to quantity, and it remains identical only in respect to quality, which differs from quantity. What shall we answer to those who insist that the soul is a body? Will they say that, in the same body, each part possesses the same quality as the total soul, and that the case is similar with the part of a part? Then quantity is no longer essential to the nature of the soul; which contradicts the hypothesis that the soul needed to possess a definite magnitude. Besides the soul is everywhere entire; now it is impossible for a body to be entire in several places simultaneously, or have parts identical to the whole. If we refuse the name of soul to each part, the soul is then composed of inanimate parts. Besides, if the soul is a definite magnitude, she cannot increase or diminish without ceasing to be a soul; but it often happens that from a single conception or from a single germ are born two or more beings, as is seen in certain animals in whom the germs divide;[52] in this case, each part is equal to the whole. However superficially considered, this fact demonstrates that the principle in which the part is equal to the whole is essentially superior to quantity, and must necessarily lack any kind of quantity. On this condition alone can the soul remain identical when the body loses its quantity, because she has need of no mass, no quantity, and because her essence is of an entirely different nature. The soul and the (seminal) reasons therefore possess no extension.
THE BODY COULD NOT POSSESS SENSATION.
6. (k.) (The body could not possess either sensation, thought, or virtue.) If the soul were a body, she would not possess either sensation, thought, science, virtue, nor any of the perfections that render her more beautiful. Here follows the proof.
IMPOSSIBILITY FOR THE BODY TO HAVE SENSATION.
The subject that perceives a sense-object must itself be single, and grasp this object in its totality, by one and the same power. This happens when by several organs we perceive several qualities of a single object, or when, by a single organ, we embrace a single complex object in its totality, as, for instance, a face. It is not one principle that sees the face, and another one that sees the eyes; it is the "same principle" which embraces everything at once. Doubtless we do receive a sense-impression by the eyes, and another by the ears; but both of them must end in some single principle. How, indeed, could any decision be reached about the difference of sense-impressions unless they all converged toward the same principle? The latter is like a centre, and the individual sensations are like radii which from the circumference radiate towards the centre of a circle. This central principle is essentially single. If it was divisible, and if sense-impressions were directed towards two points at a distance from each other, such as the extremities of the same line, they would either still converge towards one and the same point, as, for instance, the middle (of the line), or one part would feel one thing, and another something else. It would be absolutely as if I felt one thing, and you felt another, when placed in the presence of one and the same thing (as thought Aristotle, de Anima[53]). Facts, therefore, demonstrate that sensations centre in one and the same principle; as visible images are centred in the pupil of the eye; otherwise how could we, through the pupil, see the greatest objects? So much the more, therefore, must the sensations that centre in the (Stoic) "directing principle"[54] resemble indivisible intuitions and be perceived by an indivisible principle. If the latter possessed extension, it could, like the sense-object, be divided; each of its parts would thus perceive one of the parts of the sense-object, and nothing within us would grasp the object in its totality. The subject that perceives must then be entirely one; otherwise, how could it be divided? In that case it could not be made to coincide with the sense-object, as two equal figures superimposed on each other, because the directing principle does not have an extension equal to that of the sense-object. How then will we carry out the division? Must the subject that feels contain as many parts as there are in the sense-object? Will each part of the soul, in its turn, feel by its own parts, or will (we decide that) the parts of parts will not feel? Neither is that likely. If, on the other hand, each part feels the entire object, and if each magnitude is divisible to infinity, the result is that, for a single object, there will be an infinity of sensations in each part of the soul; and, so much the more, an infinity of images in the principle that directs us. (This, however, is the opposite of the actual state of affairs.)
AGAINST THE STOICS, SENSATIONS ARE NOT IMPRESSIONS OF A SEAL ON WAX.
Besides, if the principle that feels were corporeal, it could feel only so long as exterior objects produced in the blood or in the air some impression similar to that of a seal on wax.[55] If they impressed their images on wet substances, as is no doubt supposed, these impressions would become confused as images in water, and memory would not occur. If, however, these impressions persisted, they would either form an obstacle to subsequent ones, and no further sensation would occur; or they would be effaced by the new ones, which would destroy memory. If then the soul is capable of recalling earlier sensations, and having new ones, to which the former would form no obstacle, it is because she is not corporeal.