The Sentient Life-Principle

Article 3. The Sentient Life-Principle

a) Nature of the Sentient Life-Principle

We have already seen that every bodily being is made of prime matter and substantial form. Further. we have learned that in living bodies, the substantial form is the vital principle or soul. It is obvious, therefore, that the substantial form of an animal is its life-principle or animal soul.

Now, animals manifest the operations of two grades of life. They have the vegetal powers and operations as well as those distinctively sentient. The question may, therefore, arise: Have animals two souls each, or only one; and if they have but one, is this a vegetal soul with animal powers, or an animal soul with vegetal powers ? The answer is this: Animals have each but one life-principle or soul; and this single life-principle is the sentient life-principle or animal soul which is at once the radical principle of the vegetal and sentient operations of the animal organism. An animal is possessed of life in the second grade or degree (sentient life) and this grade necessarily includes the perfections of the first or lowest grade. Therefore, the animal soul is at once vegetal and sentient. More precisely, the sentient life-principle (that is, the life principle of a sentient organism) is also vegetal.

There is, of course, only one life-principle in any organism. For the life-principle is the substantial form of the organic body, and there cannot be, in the same bodily substance, a plurality of substantial forms. Now, the animal is a sentient organism; sentiency is distinctive and definitive of its very essence. Hence the one substantial form of the animal organism is the principle of its sentient life. But its sentient life involves the vegetal life. For many animal functions mingle the operations of the two grades of life in an inextricable manner. The animal reproduces, and generation is, in itself, a vegetal function; but the product of animal reproduction is a sentient organism: a vegetal function and a sentient product. The same thing is observed in nutrition and growth as manifested in animal organisms: these operations are, taken in their essential character, vegetal in nature; yet, in animal organisms, the thing that takes nourishment and grows is sentient, that is, the animal and its organic members. Hence we assert that the animal soul or sentient life-principle is at once vegetal and sentient.

Some philosophers refuse to admit that the plurality of substantial forms in a single body is a definitely impossible thing; they regard the matter as still an open question. We hold this position untenable, but we shall not pause to discuss it here. We merely offer, in addition to the reasons mentioned in the last paragraph, some items of evidence which prove beyond quibble that there is only one life-principle in each animal organism:

t. If the animal were not a single, but a dual substance; if there were in the animal two life-principles or substantial forms, one vegetal and the other sentient, we should find it impossible to explain why the operations of both principles should cease at precisely the same moment, that is, at the moment of the animal’s death. We should, that is to say, find it impossible to explain why this is always the case. For plant-life can exist and manifest itself in its proper operations without sentiency; it does so in grass and trees; why should it not go on in a dog that has ceased to be sentient ?

2. If there are two life-principles in an animal we shall find it impossible to explain their continuously, unvarying harmony of operation. There is never a “conflict” between the vegetal and sentient functions of an animal, not even in minor manifestations. The growth of an animal does not, for example, develop a type satisfactorily vegetal but unwieldy for sentient functions.

3. If vegetal and sentient life-principles exist separately in an animal we find it impossible to explain the essential interdependence of vegetal and sentient operations in the same organism. We have instanced examples of this just now when we spoke of the sentient life involving the vegetal operations, and of the two being inextricably bound up together. To illustrate further: the more perfect animals, at least, sense their food before taking it or even before finding it; thus, the sentient operation is necessary for the vegetal operation of nourishment. On the other hand, defective function in the vegetal order may impair sentient operations: thus, a sick animal (defective in vegetal function) is not so perfectly alert and capable in its sentient operations as an animal in sound health.

The animal soul or sentient life-principle is a single principle which is at once vegetal and sentient. But it is none the less essentially different from the life-principle which is merely vegetal and not sentient, that is, from the plant soul. Function follows essence (agere sequitur esse), and essentially different and superior functions or operations indicate an essentially different and superior principle whence they proceed. Now, as we have seen, the functions or operations of the animal as such are essentially different from, and superior to, the functions and operations of the plant as such. In other words, operations of plants and animals indicate the fact that here are two essences; and the difference between two essences is an essential difference. The animal, indeed, has the operations of the plant, and it manifests these more perfectly in its own way than they are manifested in a simple vegetal organism. But you cannot say of an animal that it is merely a plant. It has plant-operations, but it has more; it has operations more complex and admirable than the plant can exercise; it has sentient operations. Therefore, the animal is not only possessed of a different essence than that of the plant; the animal’s essence is also superior to that of the plant.

The sentient life-principle is,—like the life-principle of a plant,—a material substantial form, a material life-principle, a material soul. It is not, indeed, made or constructed of bodily parts, but it depends for its existence and its operations upon the organic body, which is material in structure. The sentient life-principle depends on matter; without the body it does not have actuality or function; therefore, it merits the designation of material.

The sentient life-principle is incomplete both as a substance and as an animal. Manifestly, it is not an animal, but an essential constituent part of an animal. Nor is it a complete substance, for it is not fitted to exist by itself, but depends upon the organic body for existence and operation. Therefore the sentient life-principle,—like the life-principle of a plant,—is “incomplete both in the order of substantiality and in the order of species.”

To sum up: If we are asked to describe the nature of the sentient life-principle, we say: (a) that it is an incomplete substance which,—joined with the organic body of which it is the first substantial act,— constitutes the sentient organism or animal as a complete, existing, functioning living body of the second grade of organisms; (b) that it is a single actuality in each organism, and is at the same time sentient and vegetal; or, more precisely, that it is the root-principle of both the vegetal and the sentient operations of the animal oganism; (c) that it is a material substantial reality, in the sense that it has an essential dependence on matter for its existence and operations.

b) Characteristics of the Sentient Life-Principle

1, The sentient life-principle is simple. It has no formal parts; no parts as such; no parts of its own, even though it is the vivifying principle of an organic body which has such parts. For the sentient life-principle is the substantial form of the animal body, and every substantial form has the property of simplicity.

2. The sentient life-principle is actually one, and, in the more perfect animals, it is not potentially multiple. Some of the lower, less complex animals, such as worms, may be divided into parts, and each part will continue to live, and will exist as an independent and complete individual organism. But among the higher animals this is not the case. There is nothing in the animal life-principle itself to balk potential multiplicity, for it is a material principle dependent on a divisible organism. But the great complexity and diversified functions of the higher animals appear to constitute an insurmountable obstacle to multiplication by simple partition of the organic body. The higher animals are multiplied by generation only,— that is, by the organic functional process,—and not by partition or division of the organism.

5. The sentient life-principle is generated per accidens. When animals generate or reproduce, the offspring is not a life-principle, but an animal, and this animal has a life-principle. The animal is generated per se; it is the thing which is directly reproduced; and with it, so to speak, the life-principle conies into being. For this reason the life-principle is said to be generated per accidens; that is, not in itself directly, but along with something else, viz., the generated animal, of which it is an essential constituent part.

4. The sentient life-principle undergoes corruption per accidens. Just as it is the animal which is generated, and not the bare life-principle, so it is the animal which is corrupted or dies. The animal itself dies; the animal dies per se. The life-principle of the animal passes, with the death of the animal, from actual existence; it is corrupted or dies per accidens. At the risk of some inaccuracy we may put the statement thus: the animal itself dies, and this is corruption per se; the passing from actual existence of the animal life-principle is incidental to, or accidental to, the passing of the animal, and this is corruption per accidens,

5. The lower life-principles (plant soul and animal soul) are educed from the potentiality of matter, and are reduced to the potentiality of matter.

The potentiality of matter is the sum of possibilities latent in it. Now, matter can be alive; matter can be in-formed by a substantial life-principle. We know this is so because, as a fact, matter is alive in plants and animals; and what is alive can be alive. Thus we find that to-be-alive is within the range of possibilities realizable in matter. Not that matter can of itself come to life, but matter, when actualized by a substantial life-principle can be alive, can be living matter, can be plant or animal. Matter, therefore, may be considered as waiting for the action of the substantial form which will actualize it as an organism. But we must not make this consideration too literal, for matter is pure potentiality and has no existence of its own. Keeping this clearly in mind (that matter itself has no actual existence in a formless state), we may use a very imperfect analogy, and say that the matter which is to become alive (when the substantial form is substantially joined with it) waits for its substantial form as the block of marble waits for the accidental form which is to make it a statue. And when a plant or animal is generated this waiting capacity, this potentiality, is actualized in fact, and a new organism exists. Now, in a sense, the life-principle which gives to matter actual existence as an organism, is drawn out or educed from matter, just as (allowance being made for the accidental character of the simile) the form of the statue is, so to speak, drawn out or educed from the marble block. The block of marble can be a statue, not, indeed, by its own power, for it has no power of its own to become a statue; it has only the capacity to be made a statue, and this capacity is actualized by the operation of a capable agency working upon the marble. And yet the accidental form of the statue is not something alien to the marble and attached to it from without; marble itself has the capacity for having this form, and the action of the sculptor causes this capacity of the marble to be realized in fact. And thus one is justified in saying that the accidental form of the statue is drawn out of the marble block, is educed from the marble. And if the statue displeases the sculptor; if he takes the hammer in hand and destroys the accidental form or shape which he has given the marble, so that not a feature of the image remains, the form of the statue is reduced or thrown back into the potential stage. The result of the sculptor’s destructive action is what we call a “shapeless” block of marble. And yet this shapeless block can be formed into a statue again. The potentiality to be a statue is still there. The form of a statue has been reduced to the potentiality of the marble. Now, this simile is admittedly very defective indeed. The cautious student will, however, find it valuable for its suggestion of the educing of the substantial life-principle of an organism (that is, plant or brute animal) from the potentialities of matter, and the reducing thereto of the same substantial principle when the organism dies. For matter has the capacity for existing as an organism when a capable agency (generating or parent organisms) acts or operates to give it the substantial form of an organism. And when that form is given, it is not created by the parent organisms and attached to matter externally, nor is it produced by itself and afterwards fitted to matter; but the parent organisms, by their generative act, give to matter a constitution which it is fitted connaturally to have; matter under the generative action is so constituted, so substantially formed, that it lives. And this is what we mean by saying that the life-principle of plants or brute animals is educed from the potentiality of matter. And when the organism dies, the substantial principle of life is not drawn off and kept in actual existence, to be deposited in some plant-heaven or animal-hell; no, the life-principle of the plant or animal ceases to have actual existence when the organism dies. It is not annihilated, but is reduced or thrown back to the potentiality of matter. For, while a dead plant or animal no longer has the substantial form of a living body, it still remains true that matter can have such a form.

It is important, in the present study, to reason most carefully, and to keep several important facts always in view. Such facts are the following: (a) The matter which enters with substantial form into the constitution of a body (living or lifeless) does not have actual existence by itself. There is no bare prime matter; there is no matter but in-formed matter; formless matter cannot actually exist for actual existence is a form. When matter takes new substantial form, it loses old substantial form. “The generation of one thing is the corruption of another.” In this axiom, the term generation is not limited to the production of living things, but means the substantial production of any body, living or lifeless. Thus we speak of generating water from the gases called hydrogen and oxygen. These gases, combined in due proportion under action of a capable agency, produce •water; water is generated; and at the same instant in which water comes into being, the gases pass out of actual being. The gases lose their respective substantial forms when the single substantial form of the chemical compound called water actualizes them. Thus when a new substantial form is actualized in bodies, it takes the place of an old substantial form, or of old substantial forms if the new body be substantially compounded of two or more elements. A new substantial form actualizes (generates) the new body, and the old substantial form or forms disappear (corrupt); and this all takes place instantaneously; and so “the generation of one bodily thing is the corruption of another.” When a new substantial form comes in, it drives out the old. There is no medium, no middle ground, no “no man’s land” between the two substantial forms. Therefore, we cannot view prime matter alone, for it does not exist alone. When a living body ceases to be alive, the substantial form (life-principle) is reduce^ to the potentiality of matter; but the body, the cadaver, is not formless matter. The dead body is still possessed of the outer shape (an accidental form) of the living body, and will retain it for a time; but the dead body is,—the instant the organism dies,—merely a parcel, in the shape of an organism, of various chemical elements and compounds, each of which has its proper substantial form as a lifeless substance. The substantial unity of the living body is conferred by the life-principle, and when the life-principle no longer actualizes the body, this substantial unity is instantly broken up and destroyed.

’ (&) The substantial form of an organism is its life-principle. But if this be a material form it has no actual existence by itself. There is no actually existing substantial form (if it be material, i. e., dependent on matter) except in actually existing bodies|Substantial form and prime matter must be substantially united, and then the actual body (essentially constituted of prime matter and substantial form) has actual existence. Remember that neither matter nor material form is complete either as substance or as bodily being in a definite essential kind.

(c) When a plant or animal is generated, this happens because the operating organism (or organisms, for there are usually two, male and female) produces a cell of such constitution that it has life in the same grade as the parent, yet its own life, which is not the life of the parent, but of the germinated cell as a new living organism. The materials of the new cell came indeed from the parent body or bodies, and these materials were not pure prime matter, but matter in-formed, matter with its own substantial character. The fecundation or germination of the matter resulted in the fact that the matter took on a new substantial character; its old substantial form gave place to the new, and the new substantial form was a single substantial life-principle.

In all this, we have been discussing the production and the corruption of the lower life-principles, the material life-principles, which are the respective substantial forms of plant and animal. These principles, as we have explained, are educed from the potentiality of matter, and reduced thereto at the death of the organism. But there is another life-principle found in a living body which is not material, but spiritual. This is the human life-principle or rational soul, and we shall study it in the second Part of this manual. Here we merely mention an important fact: the human soul is not educed from the potentiality of matter (for, being spiritual, it is in no sense within the possibilities latent in matter) nor is it reduced thereto when a man dies. The human soul is, in each instance, produced by the direct creative act of Almighty God, and by the same act is simultaneously infused into the body, that is, is substantially united with the body, to actualize the single human substance. When a human being dies, his soul remains in actual existence apart from the body. For the human soul is spiritual, and, although it is united in one human substance with the body (and does not merely reside in the body like a prisoner in a cell), it is not dependent on matter for its existence or those operations which are peculiarly its own.

Summary of the Article

In this Article we have studied the nature of the sentient life-principle or animal soul. We have seen that each animal has a life-principle, and that this principle is the substantial form of the animal’s organic body. We have seen that this substantial form is the root-source of all the vital operations of the animal; that it is the one and only vital principle whereby the animal lives, takes nourishment, grows, propagates, senses, appetizes, moves by local movement. We have seen that the sentient life-principle, although it is both vegetal and sentient, is, nevertheless, a principle essentially different from, and superior to, the merely vegetal life-principle of a plant. Like the plant soul, the sentient life-principle is material, since it depends for being and operation upon matter, i. e., upon the organic body of which it is the first substantial act. We have seen that the sentient life-principle is incomplete both as a substance and as an animal. We have noticed the outstanding characteristics of the vital principle of an animal, and have found that it is simple, actually one (and only in the lower animals is it potentially multiple); that it is generated and corrupted per acidens; that (like the vegetal life-principle of a plant) it is educed from the potentiality of matter, and is reduced thereto when the animal dies.