Movement in the World

Movement or motion, in a very wide sense, means any operation whatever, whether of body or spirit, of finite being or of infinite being. In a stricter sense, movement or motion means a going over from one state or condition to another. In a word, it means change.

Change (or motion in a strict sense) is, as we have seen, a characteristic of bodily being. It involves a transit,—a going over,—from one state or condition (substantial or accidental) to another. In this full sense, change is proper to bodily being, for spirits cannot change substantially, and the infinite God is not subject to any change, substantial or accidental; He is the Being ‘‘with whom there is no change nor shadow of alteration.”

Change consists essentially in the transit, the going over. But it involves two other things, viz., a startingpoint and a term or goal. The starting-point is called the terminus a quo (or “term from which’’); the goal is called the terminus ad quem (or “term to which”) and the going over from starting-point to goal (that is, motion or change proper) is called the transitus or “transit.” In addition to the three requisites of motion or change considered in itself, there are two other requirements, viz., a mover or motor-force, and a support. Nothing moves itself, absolutely speaking ; whatever moves is moved, and is moved by something other than itself. Further, movement does not occur in the void, it is a going over and requires “a bridge,” even when it is instantaneous; it requires a support. To illustrate: in the accidental change which occurs when cold water is made hot, we find the elemental requirements of change: the terminus a quo is the cold water, or, more exactly, the coldness of the water; the terminus ad quem is the heated water, or the heat of the water ; the transitus is the progress from cold to hot which the water undergoes. In addition to these three elements of change in itself, we find the other two requirements, to wit, the mover or motor-force is discerned in the fire and its action upon the water ; the support of the change is the bodily being of the water which supported, so to speak, the coldness and now supports the heat, and was the supporting reality which received the first touch of heat and held steady while this was increased in succeeding degrees.

That motion exists in the universe is a manifest fact. We have already considered this point in our studies about the characteristics of the bodily world and in our classification of bodily activity as mechanical, physical, and chemical.

b) CLASSIFICATION OF MOVEMENT

Movement, motion, or change is extrinsic if it exists in name only, and not as actual fact. Thus the pillars that are on our right as we go into church, are on our left as we come out. To say that they have changed or moved is not true in actual fact, but they do stand in a changed relation to ourselves because of our movement, and we call this an extrinsic change in the pillars. Intrinsic change is change in actual fact, not merely in name. Intrinsic change is metaphysical if it is beyond the nature or piysis of finite things and of creatural powers to produce. We have three examples of metaphysical change, viz., creation, annihilation, transubstantiation. Metaphysical change is not change properly speaking, for it lacks one or other of the internal or external requisites for change properly so called. Creation lacks the terminus a quo, for it has nothing as a starting-point. Annihilation lacks the terminus ad quem, for its formal term or final goal is nothingness. Transubstantiation lacks the support which endures under change, for it is the complete change of one substance into another, nothing of the former substance remaining. Cosmology has no concern with metaphysical change, but considers physical change or change properly speaking. Physical change is that which has a definite form,— substantial or accidental,—as its term or goal. Hence, physical change involves something enduring, something permanent, something that supports the change and does not itself change as the new form is acquired and the old form lost. In a word, physical change is a change of form in enduring matter. Physical change is substantial or accidental. Substantial change is the transit which occurs in prime matter as one substantial form is lost (corruption) and a new substantial form is acquired (generation). Since the loss and gain is simultaneous, we say that the corruption of one substance (that is, the loss of substantial form) is the generation of another substance (that is, the acquiring of new substantial form), and vice versa. The Latin phrase is, Corruptio unius est generatio alterius; generatio unius est corruptio alterius. Corruption and generation are in- stantaneous changes, not successive or gradual.—Accidental change is the transit which occurs in the gaining or the loss of accidental form. Remember that a form is any determinant or determinateness of being. Heat or whiteness or sweetness are accidental forms; location, local movement, rest, are accidental forms; increase and diminishment in quantity are accidental forms. Since’ some accidental forms can be acquired without concomitant loss of other accidental fornis (for example, light or illumination which displaces the non-being called darkness) there can be accidental generation without accidental corruption; but usually these occur simultaneously, and together they are called conversion. Accidental change is, in itself, successive or gradual (as, for example, the change which occurs by degrees as water changes from cold to warm and from warm to hot). But at the instant when accidental change begins to affect a substance we find an instantaneous accidental generation or corruption. Thus, when cold water receives the very first beginning of change to a higher temperature, this change is instantaneous, although the water thereafter goes on becoming hotter by successive degrees. Accidental change is a change in place, in quantity, or in quality (local change, quantitative change, qualitative change). The accidental change which takes place in a body by reason of its exercise of connatural activities is local, and sometimes quantitative, in mechanical ac- tivity; it is qualitative in physical and chemical activity.

To illustrate the types of physical change. Wood that is burned up, food that is turned into the flesh and blood of the eater, the living body turned to a lifeless corpse, all these illustrate substantial change. We shall speak in detail of the character and actuality of this type of change in the next section of the present Article—Accidental change may be noticed in the examples just cited : in the heating of the wood which precedes its burning, in the churning of food in the stomach and its qualitative change, in the physical and chemical changes that occur in the corpse as its components are sifted out and each drawn by proper affinities to its kind.

The following schema will help the student to fix in memory the classification of the important types of motion or change:

Metaphysical (improperly called change)

Motion or counel sustaneal [si (or change. ANS

proper) accidental { local

quantitative

change qualitative

c) SUBSTANTIAL CHANGE

The first actuality conferred upon the world was that which drew bodily being out of nothingness into existence; it was, as we have seen, an actuality conferred by the divine act of creation. Now, the state of the world as we find it, and the history of the earth as written in its geological strata, as well as our daily experience with the character and activities of bodily beings, living and lifeless, all inform us of the fact that the world has undergone and is undergoing a process, a progress, a development. While it is manifest that accidental changes are occurring all the time, it is no less evident that new substantial being is continually emerging and old substantial being is continually disappearing. Among bodies, we find no evidence,—at least no compelling or even highly persuasive evidence,—of new creations; on the other hand, it is the contention of philosophers and scientists alike that we have no annihilation. The emergence and the disappearance of bodily substances is owing, therefore,—after a first creation—to substantial generation and corruption. In a word, the world carries on by the actuality and exercise of substantial change.

Monists and philosophical atomists, and other theorists of materialistic bent, deny the existence of substantial change. Necessarily, then, they deny the actuality of substantial differences among natural bodies. Yet, as we have seen, substantial change is a fact to be acknowledged if there is any value in human science at all. We cannot come at the nature of substance by scales and test-tubes and retorts; we cannot find out what substance is by the diligence of our hands or the sharpness of our eyes. We can only know substance by our mind,—our intellect or reason,—which recognizes its existence as the absolutely necessary explanation of accidental being, and recognizes something of its nature in the activities and properties of natural bodies. All science, as well as all philosophy, recognizes differences in bodily substance as indicated by differences in the properties (static and operative) of bodies. Yet if there be but one kind of bodily substance, and no substantial change, then all physical and chemical formulas are futile things ; all laboratory science is ado about nothing. We are not prepared to accept a doctrine which would plunge us into the contradictions and inanities of skepticism. Therefore, we accept as reasonable, right, and inevitable, the doctrine which maintains that there are essential differences in bodily substances, and that bodies can lose substantial form and acquire substantial form. We accept the actuality of substantial change in the world. Nor do we accept this as a doctrine of scientific or philosophical faith ; we accept it as the conclusion of sound reason dealing with facts; our certitude on the point is scientific certitude, not the certitude of sound belief.

Nearly all scientists and philosophers of consequence are quite willing to acknowledge the difference that exists between living and lifeless reality as an essential and substantial difference. Not all, however, are so willing to acknowledge substantial difference between any two lifeless bodies. However, the evidence is all against any theory of qualified monism (inorganic monism). It is still a soundly scientific principle that when two inorganic (or lifeless) bodies manifest essentially different properties, there is a substantial difference between the bodies themselves. And when a body is changed into other bodies (as water into hydrogen and oxygen, as wood or coal into ashes and smoke) there is a substantial change if the newly emerged bodies manifest properties essentially different from the properties of the original body. Nor does this scientific principle lose force by the most recent discoveries and experiments in the world of the atom and its structural parts. If, by knocking out an electron from an atom of one substance, we have at once an atom of an essentially different substance, we cannot conclude that all inorganic substances are merely a matter of arrangement of electrons about a nucleus. True, the removal of an electron in the fashion described would be a mechanical process, but it is not unusual to find physical and chemical capacities altered by a change in mechanical movement. That such change is merely local change or mechanical movement does not tell the whole story. Physical and chemical consequences can follow from purely mechanical activity. A certain quantity of matter is required for the bare existence of any substance; and a certain structure (atomic and sub-atomic) of the matter is required for the existence of a definite kind of substance. Reduction of quantity or change of structure might be accomplished by merely mechanical means, yet the result would not be merely mechanical or a matter of local movement; it would be a result rightly called an essential and substantial change. To say that because a certain arrangement of nucleus and electrons defines the actual structure of a body, and to conclude from this fact that all inorganic bodies are “of a piece” and that no substantial differences exist among them, is surely illogical. One might as well say that, because a definite structure and arrangement of parts define a man, the removal of any one of these parts (say, head or heart) would not induce a truly substantial change in the human being. Of course, we here invade the field of organic bodies, but only for the purpose of noticing a striking analogy. The point we make is this: there often is a dependence of substantial character upon the merely mechanical arrangement or structure of a body, but this is not saying that the substance consists in the arrangement ; the substantial character of the body here in question may be said to follow upon or to depend upon the structural arrangement, but not to consist in the arrangement. Similarly,—to borrow an illustration from the accidental order,—the quality of heat or heatedness follows upon and depends upon the friction which accompanies mechanical motion, but, as we have seen, it would be jumping a gap to assert that therefore heat consists in motion.

After a first creation, the world is furnished with its continuous procession of natural bodies by means of substantial change. This is true of all emerging bodies, living and lifeless. And, as we have repeatedly observed, substantial change comes about by the fact that new substantial forms (with the exception of the spiritual substantial form of man, which is not here within our purview) are continually educed from matter, and old substantial forms are continually reduced to matter. The quantity of matter (that is, of prime matter) is constant; it is the sum of the quantity of all existing bodies. Prime matter is not quantified in itself, but only in its existence as informed matter (that is, as materia secunda) in actual bodies. When new bodies emerge upon the scene, there has been no increase in prime matter; existing matter has been newly in-formed, old forms being displaced, as the new substantial actualities come into existence.