The Vegetal Life-Principle

a) Nature of the Vegetal Life-Principle — b) Characteristics of the Vegetal Life-Principle

a) Nature of the Vegetal Life-Principle

A vegetal organism, like every bodily substance, is a composite of two fundamental substantial principles, called respectively prime matter and substantial form (cf. Chap. I, Art. 4, c.) Prime matter is the common fundamental substrate of all bodies. Substantial form is not common, but specific; and each body is constituted in its essential kind by its one (and only one) substantial form. That whereby a body is bodily is prime matter; that whereby a body is an actual body with a determinate essence and nature is the substantial form of the body in question. These two things,—prime matter and substantial form,—are the two co-principles by which a bodily being is constituted. Both are substantial; prime matter (which has no varieties but is simple and pure potentiality) is the most imperfect of substantial things, and can in no wise exist by itself, although it is not an accidental, that is, a mere mark, qualification, or characterization of something else. Substantial form is also imperfectly substantial (unless it is spiritual). In a word, prime matter and substantial form, are incomplete. They must come together in substantial union to constitute the single complete substance of a body. And when they so come together in substantial union, the body is constituted as a complete, actual, existing body of a determinate essence, nature, and substantial kind.

Now, as we have seen, the vital principle or soul of a living body is the substantial form of that body. For the life-principle or soul is the first act (that is, the first actualization, actuality, actualness) of the physical organic body. Therefore the vegetal life-principle is the substantial form of the living plant. Notice carefully the words, “of the living plant.” The higher types of organism (animals and human beings) have plant life, but, as we shall see, a plant soul is not the substantial form of either beast or man. The animal or sentient life-principle is the substantial form of an animal, and the only one (since there is not a plurality of substantial forms in the same body); and the rational, spiritual human soul is the substantial form (and the only one) in each living human person.

Since each plant has only one substantial form, and since this one substantial form is the vegetal life-principle or plant soul, it follows that all the substantial actualness or determinateness of the plant must be radically attributed to the vegetal life-principle. This conclusion is inevitable. For the only other substantial principle in a plant, in addition to the substantial form, is prime matter; and prime matter is wholly indeterminate in itself, hence it cannot be the root-source of actualness or determination of any kind whatever. Therefore it is the vegetal life-principle which makes the plant an actual body and an actual organism of the plant type. The contribution made by the vegetal life-principle (or substantial form) to each plant is actuality, substantial existence, essence, nature, organization, capacity for operation. Yet the vegetal life-principle makes this contribution only when substantially united with prime matter, or, more properly, with the organic body. Taken alone, the vegetal life-principle has not in itself the essence, nature, organization, or capacity for operation which belong to the plant; nay, it has neither actuality nor existence. It is the substantial principle of all these things in the living plant, which it makes a living plant by its substantial union with matter. For prime matter and substantial form are substantial *co-*principles; both are required; both must be present in substantial union, else the body which they should constitute does not exist. All this is mentioned to stress two important facts: first, the fact that the vegetal life-principle is the sole radical source of the actuality and operation of the plant; secondly, the fact that the bodiliness or matter of the plant is an essential principle of its constitution as an organism.

It is evident, from the foregoing study, that the vegetal life-principle is incomplete as a substance, and incomplete as a plant. Substantial it truly is; but it has no actualness and no proper operations apart from the plant of which it is a constituent substantial part. And, being but an essential part of the plant-substance, it is manifestly not completely a plant. Technically speaking, “the vegetal life-principle is incomplete both in the order of substantiality and in the order of species.” In plainer terms, “the plant soul is itself neither a complete substance nor a complete plant.”

The vegetal life-principle is a material substantial form. Not, indeed, that it is made of bodily matter but that it requires matter (in substantial union with itself) in order that it may actually exist and discharge the operations of which it is the root-source. The plant soul is called material because, in the sense described, it depends on matter in being and in operation.

b) Characteristics of the Vegetal Life-Principle

1. The vegetal life-principle is simple. Simple means uncomposed, not made of parts, and hence not divisible into parts. Every substantial form has the property of indivisibility or simplicity. And the vegetal life-principle, as we have seen, is a substantial form. The plant soul, therefore, is not made of separable parts like the organic body. It cannot itself be cut up by knife or saw or other instrument.

2. The vegetal life-principle is actually one, but potentially many. The rose-bush, for example, is one living body. Yet a gardener may make a dozen bushes out of that one body by the simple process of cutting off suitable parts from it and planting them in fertile ground. The knife of the gardener has not divided the plant-soul itself, for this, as we have just seen, cannot be done. But the organism, the rose-bush, can be divided; it is not simple; it is made up of parts. And the gardener in making his cuttings (which are thenceforth so many separate and individual rose-bushes) has actualized a capacity or potentiality of the original rose-bush to become a plurality of rose-bushes. The life-principle of the original bush was, before the cutting, actually one; but it was such a thing as could become multiple (that is, it was potentially multiple or potentially many). And the cutting actualized this capacity. The eleven new rose-bushes are now separate and individual plants. Each has its own single life-principle which is not any longer the life-principle of the original rose-bush from which the cuttings were taken. Nor is the life-principle of any of the new bushes a part of the life-principle of the parent plant. The cuttings, until severed, were parts of the original rose-bush; as soon as they are severed they are no longer such parts, but are now individual and complete plants. But the life-principle in a cutting was not, before the cutting was made, a separable part of the life-principle of the parent rose-bush. For that life-principle is simple; it is not composed of parts (as the bush itself is), and hence it cannot be divided into parts. But, while it cannot be divided into parts, it is potentially multiple. In other words, it cannot be divided, but it can be multiplied.—There are various ways of explaining the phenomenon here considered. Some psychologists prefer to say that the vegetal life-principle is not divisible per se (that is, it has no parts of its own into which it may be divided) but is divisible per accidens (that is, divisible by reason of the divisibility of the matter on which it depends for being and operation). In other words, the vegetal life-principle is not itself divisible, but is divisible inasmuch as the organic body which it vivifies is divisible into parts which can sustain life as individual plants. Others prefer to express the matter thus: the plant-soul is essentially simple, but quantitatively it is compounded or composed.

3. The vegetal life-principle is generated or reproduced per accidens. This point is evident from the foregoing. A thing generated is generated per se or it is generated per accidens. Literally, per se means “through itself”; the phrase comes close in meaning to our ordinary expressions, “of itself” or “by itself”; sometimes the simple word “itself” makes the best translation. The literal meaning of per accidens is “through that which is accidental”; and “an accident” or “an accidental” is contradistinguished from what is substantial, or, sometimes, from what is essential. The word “accidentally” is the most common translation for per accidens, but sometimes we must use a roundabout and wordy phrase to get the exact equivalent in English. The meaning of per se and per accidens in the present instance may be gathered from a restatement of the sentence which stands at the head of this paragraph. We may put it thus: the plant-soul is not generated by itself; it comes into being with the living body to which it belongs. Therefore, although the life-principle in a plant is an essential and a substantial constituent element of the plant (and not in any sense an accidental), the mode of its coming into existence is accidental to the generation of the organism which it vivifies.—In the generation or reproduction of plants, it is the entire plant that is generated. The plant itself is generated. Hence we say, the plant is generated per se; the life-principle of the plant, however, is generated per accidens.

4. The vegetal life-principle undergoes corruption per accidens. In modern casual speech the term “corruption” signifies either “rottenness” or the process by which a thing rots away. Thus we speak of the physical corruption which fills the sepulchre. Thus we speak of the moral corruption of youth by the bad conduct of their elders. But in the present instance we use the word “corruption” in the ancient and philosophical sense. It is the opposite of “generation.” Generation and corruption are not gradual processes; they are instantaneous. When, for example, a new organism comes into existence, there is a moment when it does not yet exist as an organism, and an indivisible instant later it is an organism. The gardener approaches the rose-bush, knife in hand. He begins to make the cutting. There is an instant when the part to be severed is still part and parcel with the original plant; there is a moment during the process of severing,—an indivisible moment or instant,—when the cutting ceases to be a part of the original plant and is a separate and individual plant. That indivisible moment, that immeasurable instant, is the moment of generation. Suppose again that some living body (plant or animal) is about to die. Death is instantaneous. We may speak of “dying,” and consider it as something that goes on for a longer or shorter period of time; but, in such use, the term is figurative. A thing is either alive or it is not alive; there is no middle ground between the states of life and non-life. Now, the plant or animal which we consider to be at the point of death is, at one instant, alive; the next instant, it is dead. An indivisible line has been crossed; a measureless instant has intervened between life and death. Up to a certain moment, the body was alive; after that moment it was dead; and the moment itself is not measurable. That moment, that incalculable instant, is the moment of corruption. It is in this sense that we use corruption in the present study. We assert that the soul or life-principle of a plant does not itself die or undergo corruption. No; it is the plant which dies. And when the plant dies, the plant-soul perishes. In other words, the plant is corrupted (here the word means dies) per se; the plant life-principle is corrupted per accidens, i.e., ceases to exist with the cessation of the organic existence of the plant.

Summary of the Article

In this Article we have reviewed the doctrine of the fundamental constitution of bodies (prime matter and substantial form) and have learned that the vegetal life-principle is the substantial form of the living plant. We have found that the vegetal life-principle is substantial, is a substance, but not a complete substance. We have learned that it is incomplete both in the order of substantiality and in the order of species. Further, we have learned that the vegetal soul or life-principle is a material substantial form, not in the sense that it is made of matter, but that it depends on matter. We have considered important characteristics of the vegetal life-principle, and have found that it is simple, that it is actually one but potentially multiple in each plant, that it comes into being and perishes per accidens and not per se.