Page:Popular Science Monthly Volume 14.djvu/291

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VIRCHOW AND EVOLUTION.
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able expansion of the powers which we now possess. We may think over the subject again and again, but it eludes all intellectual presentation. The territory of physics is wide, but it has its limits from which we look with vacant gaze into the region beyond. Let us follow matter to its utmost bounds, let us claim it in all its forms—even in the muscles, blood, and brain of man himself, it is ours to experiment with and to speculate upon. Casting the term 'vital force' from our vocabulary, let us reduce, if we can, the visible phenomena of life to mechanical attractions and repulsions. Having thus exhausted physics, and reached its very rim, a mighty mystery still looms beyond us. We have, in fact, made no step toward its solution. And thus it will ever loom, compelling the philosophies of successive ages to confess that—

. . . . 'we are such stuff
As dreams are made of, and our little life
Is rounded by a sleep.'"

In my work on "Heat," first published in 1863, I employ the precise language here extracted from the Saturday Review.

In this extract a distinction is revealed which I had resolved at all hazards to draw—that, namely, between what men knew or might know, and what they could never hope to know. Impart simple magnifying power to our present vision, and the atomic motions of the brain itself might be brought into view. Compare these motions with the corresponding states of consciousness, and an empirical nexus might be established; but "we try to soar in a vacuum when we endeavor to pass by logical deduction from the one to the other." Among those brain-effects a new product appears which defies mechanical treatment. We cannot deduce consciousness from motion, or motion from consciousness, as we deduce one motion from another. Nevertheless observation is open to us, and by it relations may be established which are at least as valid as the conclusions of deductive reason. The difficulty may really lie in the attempt to convert a datum into an inference—an ultimate fact into a product of logic. My desire for the moment, however, is, not to theorize, but to let fact speak in reply to accusation.

The most "materialistic" speculation for which I am responsible, prior to the "Belfast Address," is embodied in the following extract from a brief article written as far back as 1865:

"Supposing the molecules of the human body, instead of replacing others, and thus renewing a preëxisting form, to be gathered first-hand from Nature, and placed in the exact relative positions which they occupy in the body. Supposing them to have the same forces and distribution of forces, the same motions and distribution of motions—would this organized concourse of molecules stand before us as a sentient, thinking being? There seems no valid reason to assume that it would not. Or, supposing a planet carved from the sun set spinning round an axis, and sent revolving round the sun at a distance equal to that of our earth, would one consequence of the refrigeration of the mass be the development of organic forms? I lean to the affirmative."

This may be plain speaking, but it is without "dogmatism." An opinion is expressed, a belief, a leaning—not an established "doctrine,"