The Activity of Bodies

To act is to be effective, to produce a result or an effect, or to react to a force received, to undergo or experience an effect. When we speak of the activity of bodies in the material universe, we discuss their natural equipment and tendency to produce results, to be effective, to “do things,” and to react to what is done to them. Familiar instances of what we mean by bodily activity are discerned in the movement of a body from place to place; in the fact that bodies impress our senses as we apprehend them; in the leaping of flames ; in the combining of chemical elements ; in the diffusion of heat or light; in the operations of living bodies, such, for instance, as digesting, growing, sensing. We also discern activity in the response of bodies to gravitation, inertia, cohesion. No one who acknowledges the actuality of the material world is in any doubt about the existence of the activity of bodies; he has only to look around him to find it. But many who lay claim to the name of scientist or philosopher have faulty notions about the nature of bodily activity, We must look into this question. First, however, it will be well to set out a classification of the activities of bodies.

b) CLASSIFICATION OF THE ACTIVITIES OF BODIES

The bodily activity manifest in the natural world around us may be fundamentally classified as immanent and transient activity.

Immanent activity is an activity which has its chief effect in the reality which exercises it. The word immanent literally means “remaining in,” and immanent activity remains in the agent or doer which produces it. Immanent activity is always vital activity or life-activity. A living body, by its vital activity (such as nutrition, growth, sensation, appetition), tends, first of all, to actuate and perfect itself; the activity remains in the living body which produces it, and achieves its main effect there. And, while vital activities often have effects that reach out beyond the agent (that is, the doer, performer, producer), such effects are secondary and non-immanent effects. In a word, vital activity is always immanent activity (and, indeed, it is the only immanent activity) but it is regularly associated with non-immanent secondary activities. Thus the vital activity of growth is immanent in the growing body; but the same activity inasmuch as it means external enlargement and expansion brings a change in spatial relations with surrounding bodies, and this change (or activity) is non-immanent in the growing body. The tree that grows outside my window will, in another year or so, cut off my view of the garden. But it is manifest that this spread of branches (considered as an outer effect of growth) and its effect upon the open view are non-immanent activities of the growing tree. The immanent activity is the growing process, as it goes on in and for and by operation of the tree itself. In the bodily world, immanent activity is the activity exercised in, by, and for the active body; nonimmanent activity is exercised by body on other body, or by bodily part on other bodily part. Transient activity is non-immanent activity. The term transient means “going over” or “going across.” Transient activity goes across from the body that produces it to something else and produces its effect there. When the apple fell on Newton’s head (if the interesting legend be true) the effect of the falling (which is an activity) was, first and foremost, not within the apple, but upon the startled scientist. All activities of lifeless bodies are transient activities; and, as we have seen, all non-vital activities of living bodies are transient activities. The people we see in the street are exercising a vital and immanent activity called locomotion, but what we see is the outer and transient (secondary) effect of this activity. The movement of feet upon the pavement, the contact of fingers in a hand-clasp, the pursing of the lips, the stroking of the beard, all these (considered in themselves as outer activities or as the action of body on body or part on part) are transient activities. Nor does it signify that transient activity often goes on inside the active body ; this fact does not make immanent activity of it. The activity of the electrons in a non-living atom is an activity inside matter, but it is transient activity none the less; it is the activity of particle on particle, of body on body. To be immanent, a bodily activity must be vital; it must take place not only inside the living body, but it must be in and of and for the living body by a spontaneous connatural operation that is unified and organic. Briefly then, immanent activity is vital activity ; transient activity is non-vital activity, whether it is exercised by living bodies or by lifeless bodies. Transient activity is of three classes, viz., mechanical, physical, chemical. (a) Mechanical activity is the activity of local movement, such as the turning of a wheel, the flowing of water, the rising of steam, the whirling of an atom, the drive of a piston, the revolving of the earth, the swing of bat against ball. (b)

Physical activity is the activity of qualitative change, such as the increase or diminution of temperature, the brightening or dimming of illumination, the intensifying or fading of sounds, the activity of an electrical charge or shock. (c) Chemical activity is the activity of substantial change in bodies, such, for instance, as the activity of gases combining to produce water, or the activity which changes coal to smoke and ashes. Suppose we may bring together two substances which combine to produce a new substance, and in the process of combining they generate heat and manifest a visible agitation or bubbling. Here we have all three types of transient activity: the moving together of the substances and their bubbling agitation is mechanical activity; the production of heat is a physical activity; the generation of a new substance is chemical activity. Consider another example or illustration in the transient activities which accompany the exercise of the immanent activity of digestion. Food is taken and mingled with juices; the mixture is actively stirred about; its temperature, color, and other qualities undergo a change; a new substance called chyle is produced. Here again we have all three types of transient activity. Chemical activity, strictly, is the activity which affects a body in its very nature, rather than the active production of a new substance, although such a production usually follows.

c) THE NATURE OF THE ACTIVITY OF BODIES

There are two truths to be established in this place. First, we must show that bodily activity is not to be identified with the substance of the body which exercises it. Second, we must notice that bodily activity is really various, and is not to be summed up as always and everywhere a matter of local motion or mechanical activity.

I. The activity of a body is something which the body exercises ; it is not something which the body ts. Therefore we must not confuse substance with operation. Nor must we confuse substance with the power or capacity to operate. We do not identify the substance that we call a boy with the movements of the boy’s body nor with the power he has to execute such movements. We do not define the boy as a sum or complexity of movements, nor as a collection of powers or forces for bodily function. There have been, and indeed are, scientists and philosophers who present such a definition. But it is manifest that we cannot agree with them without denying the actuality of the world in which we live and move. As we have mentioned elsewhere, the proof of the actual substantiality of the world, and the proof of the reliability of our knowing-powers in reporting the existence of actual bodily substances, are undertaken in other parts of philosophy,—in ontology and criteriology,— but cosmology must take the world as an actual world, not a dream world, nor can it discuss at length the actuality of substances or the value of knowledge. We say, with scientific precision even in casual speech, that the boy is a substance which docs certain things,—walks, digests, appetizes,—but we do not say that the boy ts any of these things or a complexity of them all. With like accuracy, we say that the boy can walk and digest and appetize; we say he has the power or capacity to do these things; we do not say that he is such a power or capacity. And what we say here of the boy we must say of bodies in general. Bodies are substances endowed with capacities (or powers, or forces, or faculties) which they employ with true causal effectiveness in exercising certain functions or operations, that is, in exercising activities.—There are certain philosophers called occasionalists who deny the manifest fact that bodies have activities of their own, that is to say, that bodies exercise their own powers or forces in the activities we observe in them. The occasionalists declare that creatures are only the stage-setting, so to speak, of bodily activity, and that God directly produces all their activities; bodies are not the cause of their activities, they are merely the occasion which God uses to produce operations in them. This strange theory is in conflict with both conscious experience and with reason. That it goes flat against experience must be admitted by all; for it is manifest that the tree does its own growing, the dog does its own barking (not to mention biting), the horse actually runs, fire actually destroys the fuel, hydrogen and oxygen actually combine to produce water. That the theory of occasionalism conflicts with reason is no less manifest; for how could Infinite Wisdom produce a world of beings manifestly equipped for certain functions (consider, for example, the complex and elaborate structure of the simplest plant or animal) when such equipment is utterly meaningless? No, we must admit the necessity of the creative and preserving and concurring and governing activity of God in the existence and activity of all creatures. But we cannot admit that creatures (produced, preserved, and subject to constant divine concurrence) have no proper activities of their own,

Bodily activity is exercised by means of bodily powers. No body (indeed, no creature, bodily or spiritual) is immediately operative; it exercises its connatural operations through the medium of forces, faculties, capacities, or powers with which it is equipped. Hence we distinguish three things in the active body : the body as such; its power for activity ; the activity itself. The body as such, that is, the substance called body, is the fundamental principle or source of its activity; it is the principium quod operationis, the principle which operates. The power or capacity for operation (and this in most bodies is multiple) is the proximate principle or source of the bodily activity; it is the principium quo operationis, the principle by chich the body operates. The function or operation itself is manifestly distinct from the principles or sources whence it comes. Of these principles, the bodily substance is the mediate or remote principle; the power or capacity for operation is the immediate or proximate principle.

2. Bodily activity cannot be regarded in every instance as some phase or variety of local movement. Certain scientists have said that it can; these, in consequence, deny the value of our distinction of mechanical, physical, and chemical activities, and assert the existence of mechanical activity alone. Some of them go so far as to deny the existence of bodily substance, saying that this is merely an illusion due to mechanical action; which is much like saying that there is no ocean but that the waves are dashing high.

Local movement is movement in place or location. But there are bodily activities which produce not only new locations but new qualities, and there are bodily activities which work a change in the very nature of the bodies concerned in them. Local motion will suffice to explain the external circumstance of location; it will not suffice to explain the more intimate matter of inherent qualities, nor the truly internal fact of substantial change.

It is freely granted that physical and chemical activities are regularly accompanied by local motion, nay, that such activities are often dependent upon local motion. But this is not saying that physical and chemical activities are identified with local motion. Rubbing the hands rapidly together will produce heat, but we cannot say that the movement of the hands ts their heightened temperature.

The doctrine that the world is made up of matter and motion is called mechanicism and sometimes, less felicitously, mechanism. Many modern theories in science are more or less purely mechanistic. But mechanicism is always a theory that simplifies reality out of existence; it is a simplification that amounts to falsification. It does not cover the ground; it leaves unexplained most of the activities of bodies observed in the world of everyday experience. In special, it fails on these points: (a) It does not explain the origin of motion, which is never self-originating. (b) It does not explain the transfer or propagation of motion, for a moving body (small or large) does not move another body without coming into contact with it, meeting a certain resistance, experiencing a certain resiliency in the moment of contact. Now, resistance and resiliency or elasticity are surely activities of bodies other than the motion which manifests them. We call them physical activities, but the mechanicist has no name or explanation for them. (c) It does not explain the conservation of motion, which is never self-sustaining, but demands a motor-force different from itself.

Sometimes mechanicism takes on a modified character as encrgeticism. Physicists speak of bodily powers as energies, and distinguish these as kinetic (actual; due to motion) and potential (ready ; due to position). Kinetic energy is exampled in the falling body or the swinging pendulum. Potential energy is exampled in the poised body ready to fall, in the coiled spring ready to loose its force and make the pendulum swing. Further, physicists say that all energies are subject to certain “laws,” chief of which are the law of conservation, the law of intensity, and the law of entropy. The law of conservation of energy holds that no energy is wasted; expenditure in one activity means acquisition elsewhere, so that the sum of energies in the world is always the same. The law of intensity or of equilibrium says that one body cannot affect another except there be a difference in the intensity of their energies; when there is such a difference, the higher intensity is lowered, the lower is heightened, until equilibrium is reached and the effect is stopped. The law of entropy says that all energies tend to turn into heat-energy, and this tends to diffuse itself in space, and so is rendered “unavailable.” This tendency will continue until the world reaches an equilibrium of uniform temperature, and energy reactions will cease: thus “the world is running down.”

We have no quarrel with the handy distinction of energies as kinetic and potential. But we fail to find in these energies and in their “laws” a sufficient explanation of the activities of bodies. First of all, we cannot accept the position of the extreme energeticists who deny the substantiality of the world, deny true matter, and explain the universe in terms of a complexity of energies. We declare that energies or forces are non-substantial things, and that they cannot exist unless as the possession or equipment of actual substances. Nor can we accept the position of the more moderate energeticists who admit the existence of substantial matter but make it a poor battered subject of floating energies which have apparently no source, no support in being, no explanation for their intensity or weakness, no conceivable reason why they should act as they do. Against the energeticists we assert the claim of reason, that energy, like motion, requires a source, a motive force, a sustaining and transferring power. And, without appeal to the supernatural or preternatural, we find the required explanation in the actuality of substance (that is, of bodily substance) equipped with true forces or powers for diverse operations or activities ; and we indicate such substance as the true fundamental cause of bodily activity, and the forces or powers of bodily substance as the true instrumental causes which serve to bring bodily activities into existence.

SUMMARY OF THE ARTICLE

In this Article we have defined activity as it exists or is existible in the world of bodies. We have classified bodily activity as immanent and transient; we have distinguished transient activity of bodies as mechanical, physical, chemical. We have seen that bodily activity is a reality truly distinct from the substance of the body which exercises it; and that it is not to be identified with the bodily powers by means of which it is exercised. We have learned that bodily activity is really of three distinct types, and that the effort to reduce all these to the one type of mechanical activity is futile and ends in falsity. We have briefly discussed the errors of occasionalism, mechanicism, and energeticism.