University of Virginia Library

Recapitulation

Psychology,—the science of the human soul and its relations,—under the mechanistic theory of life, must receive a new definition. It becomes a science of man's activities as determined by the environmental stimuli of his phylogeny and of his ontogeny.

On this basis we postulate that throughout the history of the race nothing has been lost, but that every experience of the race and of the individual has been retained for the guidance of the individual and of the race; that for the accomplishment of this end there has been evolved through the ages a nerve mechanism of such infinite delicacy and precision that in some unknown manner it can register permanently within itself every impression received in the phylogenetic and ontogenetic experience of the individual; that each of these nerve mechanisms or brain patterns has its own connection with the external world, and that each is


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attuned to receive impressions of but one kind, as in the apparatus of wireless telegraphy each instrument can receive and interpret waves of a certain rate of intensity only; that thought, will, ego, personality, perception, imagination, reason, emotion, choice, memory, are to be interpreted in terms of these brain patterns; that these so-called phenomena of human life depend upon the stimuli which can secure the final common path, this in turn having been determined by the frequency and the strength of the environmental stimuli of the past and of the present.

Finally, as for life's origin and life's ultimate end, we are content to say that they are unknown, perhaps unknowable. We know only that living matter, like lifeless matter, has its own place in the cosmic processes; that the gigantic forces which operated to produce a world upon which life could exist, as a logical sequence, when the time was ripe, evolved life; and finally that these cosmic forces are still active, though none can tell what worlds and what races may be the result of their coming activities.

[[1]]

Address delivered before Sigma Xi, Case School of Science, Cleveland, Ohio, May 27, 1913, and published in Science, August 29, 1913.

[[a]]

Control blood negative; no adrenalin present.
Positive adrenalin reaction produced by fright of ten minutes' duration.
Adrenalin still present, but in lesser amounts under the influence of the longer period of fright. The glands had probably become partly exhausted.

[[b]]

Compare the well-stained, clearly defined Purkinje cells in A with the faint traces of the Purkinje cells which are barely visible in B.

[[c]]

Note the disappearance of the cell membrane and the faint nucleus and nucleolus in B in the only Purkinje cell in focus.

[[d]]

When an insect alights upon a leaf, the leaf closes upon it like a spring trap in a few seconds and digests the insect, taking, perhaps, a fortnight over a meal. Detail—lateral view of expanded leaf.