Page:Popular Science Monthly Volume 27.djvu/167

Rh to unify all our experiences, an attempt to be able to say that whereas here and here and here my experiences seemed unlike, separate, they now seem alike and conjoined.

The application of all this to man is plain; indeed, has been for these past years most impressively operative. Formerly, man was supposed to possess an intellectual and moral nature distinct in kind; in him was thought to reside a force peculiar, above and beyond all other forces. Observation has had much to say, as many believe, in contravention of these conclusions; and it is now well known that the doctrine of evolution is brought to bear on all sides of human psychology in a way special and searching. I have not here in mind the work of Spencer or Bain, or their immediate disciples. Within very recent days books have been published which show painstaking research in distinct psychological departments. Ribot has discussed the physiology and pathology of memory; Grant Allen has offered help in the "tangled territory" of æsthetics; Leslie Stephen has written a science of ethics, stating as his purpose, "to lay down an ethical doctrine in harmony with the doctrine of evolution"; G. H. Schneider, author of a work on the animal will, has just published a careful treatise on the human will from the stand-point of the modern development theory; Professor Preyer, at Jena, has set out the results of his observations on the soul of the child—observations made with greatest care three times each day during the first three years of child-life. I might extend my list at length; for this there is no need. We are face to face with the question of the relation between brain and consciousness. I have said that this relation is positive and constant, though few, except physicians, realize the meaning of such a fact. It means, in the first place, that changes of consciousness coincide with molecular changes in the brain. For every alteration in consciousness, however slight and transient, there has been a molecular change in the brain. This relation means, in the second place, that there is a physical basis for memory. Whether we accept or reject localization of functions in the cerebral hemispheres, we must believe that the cell-modifications which coincide with specific sensations remain permanently, thus furnishing a physical, organic requisite for memory. In the third place, this relation means that, in a recollection of any of our experiences, there is presupposed a renewed activity of those very portions of the brain which assisted in the experience. There are no transcendentalists so transcendental that they may transcend this direct relationship between what they are pleased to call gross matter and their sublimest ecstasy. What opinion must we form as to the nature of this relation?

We have choice of two conclusions which are alternatives. We may say the relation of brain-matter and consciousness is one of correlation, conversion—or we may say it is one of instrument to personality. Personality is here, as everywhere, a term chosen to represent a series of manifestations so alike among themselves and so unlike all