The Foundations of Normal and Abnormal Psychology/Part 1/V
Psychology, we said, deals with states of consciousness, but these states are not independent, floating in the air so to say. They are in connection with some material existence, and not with physical reality as a whole, but with some definite individual body. We must keep in mind that psychology is first of all a natural science, and the only thing it has to take into consideration is experience. Now as a matter of fact we never find a thought, an idea, a sensation setting up on its own hook and having complete independence of all physical reality. Were even such a thing possible, we could not know of it, because the only way we come to know of other thoughts is through their physical activities perceived by our sense organs. We know of the existence of other individual hate, love, anger, friendship, kindness by the physical expressions of those feelings, by the acts that accompany them. We know of the thoughts, of the emotions, of our companions, by the muscular expressions of the face, by the changes in the brilliancy of the eye, by the general bodily state, such as quietness or restlessness, by their gestures, by many other physical expressions, but principally by means of those physical manifestations known as speech. Were all those concomitant physical processes absent, there would have been no means whatever of knowing of the very existence of external states of consciousness. As an empirical science psychology studies only such states of consciousness as are connected with physical reality, or truer to say with some individualized physical being. In short, psychology treats of states of consciousness as dependent on or connected with the corporeal individual.
The meaning of the concept "corporeal individual" must not be left in a vague state. From a purely mechanical standpoint we may say, that a corporeal individual is a closely interrelated system of material parts forming a more or less stable equilibrium. This equilibrium is constantly being interfered with, by the forces of the external environment, but as long as that equilibrium maintains itself in resisting the disaggregating influences of external forces, it may practically be considered as a corporeal individual. In other words, a corporeal individual is a system of material parts organically interconnected, and functioning as one determinate whole. Any living being will answer our definition. From the lowest stage to the highest; from the monocellular amoeba to the highest, most complicated multicellular organism, we meet with the same fundamental traits, characteristic of what we term the !'corporeal individual." Now it is the mental states of the corporeal individual that psychology investigates and studies.
In our last discussion we have come to the conclusion that consciousness depends on the corporeal individual and can only be known from physical, bodily manifestations. Each living being manifests some activity in its reactions to the stimuli of the external environment. Now what are the reactions characteristic of consciousness? Where are the distinctive marks that stamp a physical manifestation with the impress of psychic states? The only sure way to tell is by purposive activity. We know that our neighbor is conscious, because , of his active purposive life. When a fly is on his nose, he raises his hand and brushes it away; he knows how to walk and preserve equilibrium; avoids obstacles; lives in a house for protection from the changes of weather and from harmful intruders; seeks shelter from rain; dresses himself warmly on a frosty winter day; a thousand other movements all of them expressive of purposive activity tell us of our neighbor's consciousness, intelligence. The stone on the road changes its place according to the influences of incident forces; the grain of dust is blown hither and thither by the wind; they do not show a more or less definite purposive activity under changing circumstances. The disturbance of their equilibrium does not stimulate them to induce changes in the external environment, changes that would tend to restore that lost equilibrium: They, therefore, have no purpose. (For a purpose is the tendency to realize some external action which is useful or indispensable to the life-existence of the particular individual being. The tendency to the maintenance of a definite activity in opposition to the onset of disturbing forces of the environment in order to restore the lost equilibrium, may be considered as the universal formula for purposive life in general.
This formula holds true of all animal life. The man in running after the car has purpose, so has the cat in chasing the mouse, so has the deer in fleeing from the hunter. The very amoeba, that lump of protoplasm, in extending its pseudopodia to draw in the bit of nutriment, possesses the germ of purposive activity, and some primitive psychic state must therefore be ascribed to it. Life is essentially purposive in its nature. Wherever, therefore, we meet with life, there some form of psychic state, however primitive and elementary, must be present. Psychic states stand in the most intimate relationship to life activity. The two in fact cannot be separated. Psychosis is concomitant with biosis. Psychologists as well as physiologists all agree thus far, that there is no psychosis without neurosis; some go further and affirm that there is no neurosis without psychosis; I think, we are closer to the truth, if we advance still further and assume, that there is no biosis without psychosis. Psychic states must be predicated not only of highly organized animals, possessed of a nervous system, but also of the most elementary monocellular organisms.
The evolutionist especially must accept our last conclusion, for he will agree that consciousness did not come into existence per saltum, he will acknowledge that the germs of conscious life characteristic of the highest organized being must already be present in the lowest types of life, out of which developed the higher, the more complex organisms.
We are now in a position to define the scope of psychology.
Psychology is the science of psychic states both as to content and form, regarded from an objective standpoint, and brought in relation to the living corporeal individual.