Chapter 9

How the sensitive soul can multiply but not divide

455. From knowledge of the simplicity of the sensitive soul we move to its indivisibility. Some Scholastics maintained that brute souls were extended and divisible in general.(205) Others distinguished between perfect and imperfect animals. The souls of the latter were extended and divisible; those of the former, indivisible. Suarez himself speaks in several places of divisible souls:

456. It seems clear to me that these authors arrived at their opinion solely because they did not consider that the soul is only the principle of feeling (the sentient principle), and that such a principle has to be essentially simple. If not, it would not be a principle. Their mistake was not due to lack of ability, which was highly developed in some of them, but because the method of investigation was still not perfected when they flourished. Instead of examining the soul directly through internal observation, they reasoned about it without prior observation, applying the general principles of ontology, form, matter and so on. These principles cannot be applied to an ens still little known through observation. These writers foundered on the same rock which accounts even today for our metaphysical authors who, however, are far less excusable. They undertook to resolve the question: 'What must the soul be in order to satisfy our ontological principles' (that is, their prejudices), rather than the other question, the only one that the philosopher should propose: 'What is the soul?' Only from knowledge of what the soul is can the philosopher arrive at the true, ontological principles which express the order of being in general.

457. Observations had already been made in antiquity on the conservation of life in bodies that had been severed or divided into parts. Aristotle, a great observer, distinguished between perfect and imperfect animals. He very wisely said that the former were 'like many animals joined together'.(207) He also noted that tortoises whose hearts had been removed lived a long time.(208) Averroes reports that he had seen a ram going headless and, according to Avicenna, had seen a headless bull take two steps.(209) Similar facts are reported by Tertullian,(210) St. Augustine(211) and others.

In place of the direct observation of the soul given by consciousness, we could apply an ontological argument to these external, extrasubjective facts, but this would inevitably produce errors about extension and the divisibility of sensitive souls. We would reason as follows: if a polyps, when divided into parts, becomes many living animals, the first soul has either divided or perished; in its place two other souls have been infused. Do these souls come from corruption of the first soul, or from matter, or were they created by God? There would be innumerable difficulties, and to solve them, we would be irresistibly tempted to say what seems easiest, that is, that the first soul has divided neatly into two halves.

458. On the other hand, if observation and right reasoning tell us that the soul's substance lies in the principle of feeling, must we not say that the sentient element is necessarily one and simple in every animal, and that there are as many sentient principles as animals? Surely, we will understand at once that the extended is simply the felt, and that only what is extended can be conceived as susceptible of division? Is it not clear that if division can take place solely in what is extended, the soul as sentient cannot be conceived as divisible but is in fact the very opposite of what is felt?

I know that some people will be surprised at this. An imperfect ontology invades minds; we all create our own ontology from the nature of bodies, as if these were the only entia from which to draw the nature and intrinsic order of every ens. Consequently, there are many objections, and they all begin with the phrase, 'How is it possible...?' But ignorance of how a thing can be does not make it impossible when it is a fact of experience. My reply is St. Augustine's straightforward logical reply to precisely the same argument. Evodius had countered St. Augustine's defence of the soul's simplicity with the fact that when a polyps is cut in pieces, all the pieces remain alive:

In fact, possible objections against a truth, even if apparently insoluble, can never destroy, with good logic, what is directly and solidly demonstrated. On the other hand, every excellent doctrine causes the greatest difficulties to the masses because of its profundity and abstruseness. The wise either solve the difficulties or, if not, maintain the most firm conviction of the truth they had previously known.

459. However, we will not find the matter as difficult to understand as it first appears if we obtain our notion of the soul and its activities solely from consciousness and internal observation. The results will then silence the presumptuous prejudices ceaselessly murmuring in our spirit because we will have found what I have pointed out, namely:

1. That which is extended and felt can exist only in that which is unextended, simple and sentient.

2. The sentient element and the felt element, having no third thing between them, form one single, simple feeling which has two poles, as it were, of which the unextended pole is the principle, and the extended pole, the term.

3. The unextended sentient element is thus totally present in every part of the extended felt, precisely because no part could be felt if there were no sentient element, which together with the felt element forms one, single feeling.(213)

4. The sentient is limited by the felt, which is the term of its act. Thus, the sentient must always be where the felt is. Contrariwise, where there is no felt, there is no sentient, because the latter feels only through the felt, just as the felt is felt only through the sentient, as I have explained above.

5. An extended, corporeal matter underlies or adheres to the felt, which is bound to and dependent on this matter.(214) If the matter is withdrawn or changes in extension, the felt also ceases or changes its extension.

6. An extended, continuous felt can therefore divide into many parts when its matter divides, and form two or more felt elements without any communication between them.

7. There is no a priori reason why the two or more parts into which the felt element of a particular extension divides should cease to be felt; feeling as such has no dependence at all on the quality or shape of the extension. Before a felt continuum divides into two, feeling (and therefore the whole sentient element) is present in every point of the extension. In the same way, it is natural that a feeling and the sentient principle remain in all the points of the divided, discontinuous parts.

8. The sentient principle, although existing totally in every part of every felt continuum, is one because the continuum is one and without parts. For the same reason, when the felt divides into many continua, sensitive activity multiplies, because it now resides not in a single continuum but in many, separate continua.

460. This multiplication of the sensitive principle is difficult to understand, because our phantasy easily imagines the principle as some kind of complete, subsistent being without a felt element, a kind of very tiny body. But this is not the case; we must rid ourselves of such an imaginary being and concentrate our attention on the nature of the thing, namely, that 1. in nature there is only the felt, 2. the sentient is essentially united to the felt as felt, and 3. the sentient feels the continuous felt without feeling itself, because an animal felt cannot reflect upon itself in any way; indeed the word 'self' is not applicable to it. If then the principle feels only the felt and is sentient only in so far as it feels, it is clear that when the felt divides into two continua, the sentient will feel them both; on the one hand it does not feel itself, and on the other, it cannot maintain its identity in both felt elements because they are divided. This is precisely multiplication.

461. We must therefore conclude that although every sensitive soul is simple and indivisible, it is also multipliable.(215)

Notes

(205) Scotus, In IV, dist. 44, q. 1, art. 1; Durando, In I, dist. 8, 2nd p. dist., q. 3, n. 10; Capreolo, In II, dist. 15, q. 1 et ultimum contra ultimam concl.; Marsilius [of Ingen], In II, q. 11, a. 1; and De gener., q. 11 and 12; Egidius, In I, dist. 8, 2nd p., q. 5; Pomponazzi, bk. 1, De nutriente et nutrito, c. 4; Peter of Mantua, De primo et ult. instanti; John of Janduno, De Anima, II, q. 6; Apollinare, De Anima, q. 6, and John of Saxony, De generat., I, q. 10 and 11.

(206)Anima, bk. 1, c. 2, n. 19. Cf. also Disput. Metaph. d. 15, sect. 10, n. 32. - In chapter 13 of the first book of the Trattato dell'anima, he undertakes to show that the indivisibility of the souls of perfect animals can be maintained together with the divisibility of imperfect animals. Baldassar Alvarez adds a note, however, stating that Suarez did this solely because of St. Thomas, who holds this opinion about perfect animals.

(207) De iuventute et senect., c. 50.

(208) De Anima, 1, text. 67, 93; De brevitate vitae, c. 3, and De iuventute et senect, c. 1.

(209) Physicor., 7, text. 4.

(210) De Anima.

(211) De quantit. Animae.

(212) De quantitate Animae, c. 31.

(213) St. Thomas shows that the soul is present throughout the whole body. Otherwise the 'whole (that is, the composed entity) would not naturally be a single thing but merely a composition of parts'. He also shows that the soul is totally in every part of the body. Because of its simplicity, it must possess the full perfection of its species wherever it is: 'Simple forms and substances possess a perfect species per se' (not through 'the conjunction of essential principles' which is how composed entities have it). Q. de Anima, art. 10.

(214) Suarez, although erroneously admitting some divisible souls, confesses that the dependence of some souls on matter does not necessarily mean they are divisible: 'There is no necessary connection,' he says, 'between the two properties of divisibility and dependence on matter. The fact that indivisibility is a consequence of immateriality does not prove that the former cannot be found without the latter. There is no repugnance between indivisibility and dependence on matter. In fact, greater perfection is required to make a form independent than to make it indivisible, as we have seen in the case of a spiritual accident, which is indivisible yet dependent. Indivisibility can therefore stand with dependence' (De Anima, bk.1, c.13: 9).

(215) St. Jerome agrees that the souls of beasts propagate ex traduce [by transference], that is, 'by transference of flesh', but denies this to the human soul: 'Do humans,' he asks, 'like animals, propagate by transference?' (Ep. 61, ad. errores Io. Hieros.). The expression 'by transference' however does not properly express the origin of sensitive souls. These multiply solely by division of the felt without needing anything else, although the division takes place in many ways according to certain conditions.