SOUL

In its most ordinary present-day usage, the term "soul" (Gr. ψυχή; Lat. anima ), when used alone, refers to the human soul; to say soul is to mean human soul. If one intends to speak about other sorts of soul, he uses expressed qualifiers; e.g., he says plant soul, or animal soul. There is nonetheless a use of the term "soul" that means simply a principle of life, or a source of life activities, at least that of nourishing. According to this usage, soul designates the mark of a living thing, or what separates the living from the nonliving; soul in this sense is the concern of this article.

Early Greek Views. The Greek predecessors of Aristotle fastened on two characteristic marks that distinguish what has soul in it from what has not: (1) movement, and (2) sensation or knowledge; each of these is traceable to their views on the first principles of things (see Aristotle, Anim. 403b 25–28). Those who paid special attention to movement thought that soul ought to be identified with the first principle, which is most capable of originating movement. democritus, e.g., held that soul is composed of spherical atoms, which because they are spherical are most suited for motion, and hence are most in a state of motion. Diogenes's argument was in form identical with that of Democritus; but for Diogenes, air was the element most capable of originating movement, because it is the finest in grain. Anaxagoras's view, though obscure in many respects, seems to have been that soul is the source of movement, without itself being in

motion; seemingly, therefore, it is a first principle in some respects unlike what is material or a body.

Those who expressed a view on soul from the viewpoint of sensation or knowledge had, as a basic conviction, that like is known only by like. Thus, if one analyzes what soul knows, one can say what soul is. According to empedocles, the soul knows all natural things, and natural things can be analyzed into four intrinsic constituents, namely, fire, air, water, and earth, and two extrinsic principles, namely, Love and Strife. Soul, therefore, is a combination of the six. Otherwise, it would be difficult to see how soul can know these things. According to plato, soul knows not only natural and changing things, but also changeless things—the Numbers, the Forms or Ideas, and the Geometricals. Since all things have whatever reality they possess because of a participation in the Numbers, and since soul knows all things, soul must be a number. Another way of showing that the soul is a number (or a combination of numbers) is to consider the fact that soul knows in different ways: (1) by intuition (hence the number one is of the nature of the soul, since intuition grasps in a single flash); (2) by science (hence the number two, since in science the soul moves from one thing to a second, i.e., from premises to a conclusion); (3) by opinion (hence the number three, since soul here moves from premises to a conclusion but with the fear that some third thing, rather than the conclusion, may be true); and (4) by sense (hence the number four, because it takes four points to determine a body, and the soul knows bodies by sense).

A brief reflection on the views just recorded reveals a third characteristic mark of soul, namely, incorporeity. But two senses of incorporeity can be discerned: (1) a strict sense, as in the case of Plato's Numbers, which are neither material nor bodies; this is perhaps also implied in Anaxagoras's view of soul as the origin of motion, itself not in motion, hence possibly itself not a body; and (2) a looser sense, as in the case of Democritus's spherical atoms and Diogenes's air—in the sense of something subtle or rarefied, but nonetheless a body or material.

Preliminaries to a Definition. Of the many criticisms aristotle makes of his predecessors' views on the soul (Anim. 403b 20–411b 31), two are quite basic: (1) If one is to have a complete account of soul from the viewpoint of motion, one ought to investigate all that is implied in motion. If there is motion, then there is both a mover and a moved; in the mover there must be the ability to move, i.e., to originate motion; in the moved, the ability to be moved. The mover in this case is said to be the soul; the moved, the body. Thus, one ought not simply to put his finger on the source of soul's ability to move the body, e.g., Democritus's spherical atoms or Diogenes's air; one should also try to put his finger on the source of the body's ability to be moved by the soul. One should perhaps ask such questions as: What are the structural specifications of a body moved by soul? None of the views of Aristotle's predecessors looks to the condition of the body qua moved by the soul; all of them look only to the condition of the soul qua mover of the body. (2) Aristotle observes that all the views on soul proposed by his predecessors fail to take into account all types of soul. To say something about soul from the viewpoint of local movement, or of sensation or knowledge, or of respiration, is not to talk about all kinds of soul, for it is obvious that not all living things move about locally, nor do all of them sense, nor do all of them breathe. A complete account of soul ought to consider all types of soul. And this is why Aristotle begins his own account of soul by proposing a common definition of soul, i.e., one applicable to all its types without specifying what is distinctive of any given type; and why he carefully specifies the sort of body that is the appropriate subject having a soul (see Anim. 412a 2–414a 28).

The question, What is it?, which is fundamental for philosophers and which asks for a definition, is not properly asked about a thing until one knows that there is such a thing. But to ask: Is there such a thing as soul? presupposes having assigned a meaning to soul. Now, if soul is taken to mean the source or principle of life activities, namely, whatever there is in all things we call living that distinguishes them from those we call nonliving, then it is clear that the question: Is there such a thing as soul? is answered by answering the question: Are there living things? It is clear therefore that there is such a thing as soul, because it is clear that there are living things.

What follows is a brief presentation of Aristotle's two common definitions of soul, as commented on by St. thomas aquinas, and as clarified with examples from modern science, wherever they are of service. Aristotle's method is that of division. He begins by laying out two sets of distinctions. The first set:

1. What exists, i.e., being, is either a substance, i.e., an independently existing subject, like Jack; or an accident, i.e., something that exists in an independently existing subject as some sort of modification of it, like Jack's height.
2. Substance, according to its meanings or senses, is either matter, which is potency and as such does not exist; or form, which is act, and as such does not exist, but which accounts for the existence of matter and of the composite (such a form is said to be a substantial form—see matter and form); and the composite (i.e., what is composed of matter and form), which is the actually existing thing, such as Jack.
3. Actuality or entelechy is either like knowledge possessed (this is first actuality) or like considering knowledge possessed (this is second actuality).

The second set:

1. Substance, according to its types, is either a body (i.e., a corporeal substance) or a spirit (things such as an angel or God). (see angels, 2.)
2. A body is either natural, which is such that both its matter and its form are substantial; or artificial, which is such that only its matter is substantial, its form being accidental. The form of an artificial body is man-given. A natural body is more perfectly a substance than an artificial body, since both its matter and its form are substantial.
3. A natural body is either nonliving, such as a stone, or living, such as Jack. Anything that at least vegetates, i.e., keeps itself in existence by absorbing nourishment from its environment, is said to be a living body.

First Definition. From the second set of distinctions, it is easy to see that a living body is a natural body and a substance. Since a living body is an actually existing thing, such as Jack, a living body is a substance in the sense of a composite (see substance in the first set). Therefore, a living body has a natural and substantial matter and a natural and substantial form; a form that accounts for its being alive, and a matter that is its potentiality for being alive. Thus, soul is the form or actuality of a natural body with a potentiality for being alive. Indeed, soul is the first actuality of such a body. Soul is actuality in the sense in which knowledge possessed is actuality; for soul is presupposed to life activities. Life activities are actualities in the sense in which actually considering what one knows is actuality; actually considering what one knows presupposes what one knows. To say that soul is the first actuality of such a body is to say that soul is such a body's substantial form.

But life activities presuppose not only soul. They presuppose also a certain sort of natural body, a body having life potentially in it. Such a body is composed of certain sorts of natural elements and compounds, and is productive of certain others whose natural activities contribute to life activities. For example, digestion is performed through the natural activities of HCl, among others. Such a body is also an organized body. Witness those things, i.e., plants, in which are found what men take to be the minimum manifestations of life. The plant has diverse bodily parts ordered to diverse functions. Functionally ordered parts are organs; and a body with such parts is said to be an organized body or organism.

In light of this analysis, it can be said that natural organized body stands in the same relationship to soul as potency does to actuality. But this proportion must be properly understood. There are two senses of the potency-actuality relationship: (1) the sense in which marble, for example, before the change in which it becomes a statue, is in potency to the shape; it is as something perfectible in relation to the perfection (the shape) it is about to acquire; (2) the sense in which the marble, after the change has been completed, is in potency to the shape it has acquired; it is as something perfected in relation to the perfection it possesses, the perfection being no part of the marble as such. Natural organized body, as it appears in the definition of soul, is in potency to soul in the second sense just distinguished.

Second Definition. Aristotle's second common definition of soul, namely, the primary principle whereby we live, sense, move, and understand, is formulated in order to be used as a middle term for arriving at the first common definition by the method of demonstration.

Types of Soul. There are three types of soul, distinguished in terms of the extent to which activities commonly attributed to living things transcend the activities of matter in its nonliving states; or, in another way of putting it, in terms of the extent to which these activities transcend anything that is found in the makeup of the natural organized body of a living thing (see St. Thomas, ST 1a, 78.1). There is an activity of soul that so transcends anything in the makeup of a natural organized body, that it is not even performed by any bodily organ; this is the activity of the intellectual soul (see soul, human). Below this, there is an activity of soul performed by a bodily organ, but not through the natural activities of the elements and compounds that constitute the organ; this is the activity of the sensitive soul. Of course, such elements and compounds and their activities are required for this activity of soul, not in such a way that it takes place by the power of these elements, but only for keeping the organ properly disposed. Lastly, there is an activity of soul that is performed by a bodily organ and by the activities of certain natural elements and compounds; this is the activity of the vegetative soul. The transcendence of this activity is seen clearly in nourishment; it is seen even more clearly in the process of reproduction.

Parts of Soul. Since soul performs diverse sorts of activity, it is often said that soul has diverse parts, a part for each sort of activity. Since soul is not a body, but the first entelechy of a body, these parts of soul cannot be quantitative parts; hence soul is not quantitatively divisible into them. These parts are nothing other than the potencies or powers the soul has for performing diverse sorts of life activity; thus, if one says that soul is divisible into these parts, the meaning is simply that these parts are distinguishable from each other by definition; each is defined in terms of its object (see faculties of the soul). These parts are often called power parts, to distinguish them from quantitative parts; and the soul, a power whole. The following will make clear the difference between power parts and quantitative parts: (1) quantitative parts are "spread-out" parts, whereas power parts are not; (2) quantitative parts are homogeneous, whereas power parts are heterogeneous—there being as many different sorts of parts as there are different activities; and (3) quantitative parts are intrinsic constituents of the whole, whereas power parts are not, since the soul is something substantial and the powers of the soul are merely accidents.

Modern Thought. In modern thought, say from the time of R. descartes to the present, man's concern with the problem of soul has been: (1) a concern with the human soul, largely with the problem of the relation between man's body and soul (see soul-body relationship); and (2) a concern with the problem of life, turning mainly about the issue of mechanism versus vitalism (see mechanism, biological; vitalism).

See Also: soul, human; immortality; soul, human, origin of.

Bibliography: j. e. royce, Man and His Nature (New York 1961). a. m. hoffstetter, "Viruses: Are They Alive?" New Scholasticism 31 (1957) 297–316. r. taylor, Metaphysics (Englewood Cliffs, N.J. 1963). m. j. adler, ed., The Great Ideas: A Syntopicon of Great Books of the Western World, 2 v. (Chicago 1952); v. 2, 3 of Great Books of the Western World 2:791–810. c. mazzantini, Enciclopedia filosofica, 4 v. (Venice-Rome 1957) 1:222–239. r. eisler, Wörterbuch der philosophischen Begriffe, 3 v. (4th ed. Berlin 1927–30) 3:1–22.

[j. bobik]