That an idea is a force that shows itself as a mode of motion is borne out, to begin with, by the fact that its action conforms to that of all the other forces we know, in being, first, inevitable, and secondly, impersonal. This, so long as we regard ideas only in bundles, as my mind or your mind, is not apparent, but becomes evident so soon as we analyze mind into its successive simple parts, ideas, and consider them.
Some years ago, Carpenter came across what he regarded as an astonishing abnormal mental phenomenon. It was this: that at times the mere thought of a bodily movement was able of its own instance actually to bring that movement about. Lotze improved upon this by showing that the phenomenon occurred with much more commonness than was supposed. Finally the discovery was made, scarcely second to any in this age of discoveries, that this startling phenomenon was no abnormality at all, but the normal function in all its primitive nudity; that every motor-idea, that is, every idea of a bodily movement, instantly produces that movement when not inhibited by other ideas.
