Page:Popular Science Monthly Volume 39.djvu/615

This page has been proofread, but needs to be validated.
THE DOCTRINE OF EVOLUTION.
597

The argument here set forth is my own. When I first used it I had never met with it anywhere in books or conversation. Whether it has since been employed by other writers I do not know, for during the past fifteen years I have read very few books on such subjects. At all events, it is an argument for which I am ready to bear the full responsibility. Some doubt has recently been expressed whether Mr. Spencer would admit the force of this argument. It has been urged by Mr. S. H. Wilder, in two able papers published in the New York Daily Tribune, June 13 and July 4, 1890, that the use of this argument marks a radical divergence on my part from' Mr. Spencer's own position. It is true that in several passages of First Principles there are statements which either imply or distinctly assert that motion can be transformed into feeling and thought—e. g., "Those modes of the Unknowable which we call heat, light, chemical affinity, etc., are alike transformable into each other, and into those modes of the Unknowable which we distinguish as sensation, emotion, thought: these, in their turns, being directly or indirectly retransformable into the original shapes "(First Principles, second edition, 1867, p. 217); and again it is said "to be a necessary deduction from the law of correlation, that what exists in consciousness under the form of feeling is transformable into an equivalent of mechanical motion," etc. (First Principles, second edition, p. 558). Now, if this, as literally interpreted, be Mr. Spencer's deliberate opinion, I entirely dissent from it. To speak of quantitative equivalence between a unit of feeling and a unit of motion seems to me to be talking nonsense—to be combining terms which severally possess a meaning into a phrase which has no meaning. I am, therefore, inclined to think that the above sentences, literally interpreted, do not really convey Mr. Spencer's opinion. They appear manifestly inconsistent, moreover, with other passages in which he has taken much more pains to explain his position (e. g., Principles of Psychology, pp. 158-161, 616-627). In the sentence of p. 558 of First Principles, Mr. Spencer appears to me to mean that the nerve-action, which is the objective concomitant of what is subjectively known as feeling, is transformable into an equivalent of mechanical motion. When he wrote that sentence perhaps he had not shaped the case quite so distinctly in his own mind as he had a few years later, when he made the more elaborate statements in the Psychology. Though in these more elaborate statements he does not assert the doctrine I have here maintained, yet they seem consistent with it. When I was finishing the chapter on Matter and Spirit, in my room in London one afternoon in February, 1874, Mr. Spencer came in, and I read to him nearly the whole chapter, including my argument from correlation above mentioned. He expressed warm ap-