Page:Popular Science Monthly Volume 28.djvu/615

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A THINKING MACHINE.

fact. It may be inconceivable, but at any rate it exists. Logic may demolish it; ridicule may explode it; metaphysics may explain it away; but, in spite of them all, it continues still imperturbably to be, and to perform the thousand-and-one incredible functions which argument conclusively and triumphantly demonstrates it can never compass. Call it materialism or what else you like, experimental physiology has now calmly demonstrated the irrefragable fact that on the brain, and on each of its parts, depends the whole of what we are and what we feel, what we see and what we suffer, what we believe and what we imagine. Everything that in our inmost souls we think of as Us, apart from that mere external burden, our body, is summed up in the functions and activity of a single marvelous and inscrutable organism, our human brain.

But, though physiology can tell us very little as yet about how the brain does its work, it can nevertheless tell us something; and late researches have made such a difference in our way of looking at its mode of activity, and have so upset many current and very crudely materialistic errors, that it may perhaps be worth while briefly to state, in popular and comprehensible language, how the organ of thought envisages itself in actual working process to the most advanced among our modern physiological psychologists.

Let us begin first with the old-fashioned and, as we now believe, essentially mistaken view—the view which found its fullest and most grotesque outcome in the spurious science of so-called phrenology, but which still lingers on, more or less carefully disguised, among the "localizations" and "specific energies" of many respectable modern authorities.

According to this superficial view, overtly expressed or implicitly suggested in different cases, each cell and ganglion and twist of the brain had a special function and purpose of its own to subserve, and answered to a single special element of sensation or perception, intellect or emotion. In a certain little round mass of brain-matter, in the part of the head devoted to language (if we push the theory to its extreme conclusion), must have been localized the one word "dog"; in the next little mass must have been localized "horse"; in the next, "camel," in the next again, "elephant," and so on ad infinitum. Here, a particular cell and fiber were intrusted with the memory of the visible orange; there, another similar little nervous element had to do with the recollection of the audible note C flat in the middle octave of a cottage piano. Thus reduced to its naked terms, of course, the theory sounds almost too obviously gross and ridiculous; but something like it, not quite so vividly realized or pushed so far into minute detail, was held not only by the old-fashioned phrenologists, but also by many modern and far more physiological mental philosophers.

When we come to look the question in the face, however, the mere number of cells and fibers in the human brain, immense as it undoubt-