ACTION. In psychology, a term used broadly to cover all forms of muscular move ment. We speak, e.g.. of the action of the heart, or reflex action, etc., as well as of impul sive or voluntary action. There is, however, a growing tendency to reserve the word action for such bodily movements as have conscious antecedents and concomitants (movements for which there are conscious motives, and of which we are conscious, as they run their course in lime), and to employ the general term "move ment" for movements which are of an uncon scious. purely physiological, character. We shall therefore speak in this article of impulsive and voluntary fiction, but of reflex movement.
The problem which action sets to psychology is twofold. We have. in the first place, to trace the genesis and development of action; and in the second to analyze the active consciousness, to determine the constituent processes in the various forms of motive.
1. There are two opposed theories of the gen esis of action. The first asserts that all conscious actions have developed from reflex movements. The reflex movement is the direct and definite response of the organism to a particular stun ulus. A frog whose brain and medulla have been removed will draw up its leg if the foot be pinched; the pupil of the human eye contracts under the influence of light, and expands again as the light is diminished. Mechanical and unconscious movements of this kind are, the theory holds, older than consciousness. When mind appears, it finds such movements ready to its hand; it avails itself of them for conscious purposes. So the animal's movements. at first automatic and simple, grow more and more com plex, and have more and more of the element of consciousness imported into them. The main arguments for the position are as follows. (a) Spontaneous movements are to lie observed in children and young animals: movements that are neither reflex movements nor voluntary actions, but random discharges of the excess of energy stored in the healthy organism. These movements furnish a varied supply of active experience, certain items of which must, by the law of chance, prove to be positively pleasur able, while others will at least be less unpleasant than the experiences preceding them. When ever active experience and pleasure are thus coin cident. attention is drawn to the movement, which is elaborated into voluntary action. (b) From the physiological point of view, the move ments of the lowest organisms, as well as the movements carried out by means of the lower nerve-centres of higher organisms, are of the reflex type. And even the most complex of
voluntary actions can be atsimilated to this type on the neural side: for the physical correlate of such action is simply the reflex arc, with its central portion made longer and more circuit ous.
Neither of these arguments is, however, free from objections. In the first place. different observers differ as to the range and scope of the spontaneous movements of infancy. Some restrict them within very narrow limits, where the play of chance coincidence.would be ineon siderable; others assert that they can, one and all, lie reduced to incipient voluntary actions and imperfect hereditary reflexes. Moreover, the theory presupposes that the sensations and perceptions aroused by moving appear, in point of time, before the pleasure achieved by the m OVQ111 cut or the voluntary impulse toward it. But this means that mind is built up piecemeal, whereas there is reason to think that con sciousness is a single tissue, every strand of which is given with every other. Again, it is difficult to understand the mechanism by which pleosurahle movements are selected. Granted that a movement chances to bring pleasure. how is its repetition brought about? Can we form any clear idea of the way in which a motive is prefixed to the sensation series? As for the second arg,ument, it is asserted as evident that the simplest form of sensory-motor coOrdination need not be the earliest. There is a primitive simplicity: but there is also a sim plicity of reduction and refinement. Again, the statement that the movements of the lowest organisms are reflex in character is said to beg the question: the original theory assumes out right that there is a strict parallel between the growth of the race and the growth of the indi vidual, between phylogeny and ontogeny, and does not take into account the fact that the individual conies into the world endowed with a rich inheritance of neuro-muscular coiirdina tions. And, lastly, even if the neural substrate of voluntary action be in structure no more than a highly complex reflex arc, still the oppo nents of the theory point out functional differ ences: the reflex is uneonlcions, while the func tioning of the central cells of the voluntary are is accompanied by consciousness. So we come face to face once more with our original problem.