Page:Popular Science Monthly Volume 13.djvu/467

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Whatever voluntary muscular movements we may make, therefore—be they ever so new and wonderful to ourselves or to others—we make because we can; because they are already accomplished facts packed up in our inherited organization. The truth of this proposition makes its converse also true, and the proposition itself receives additional confirmation from the truth of the converse, namely, whatever muscular movements are beyond our voluntary control are so because they are not accomplished facts in our inherited organization. Take, for example, the familiar, schoolboy, muscular puzzle, which seems to be a very simple movement, and very easy of execution; yet we doubt whether it has ever been really mastered, even after the most protracted efforts, so that it could be executed with the automatic ease and dexterity with which we execute our voluntary movements. It is easy enough to extend the forefinger of the right hand, and revolve it rapidly so as to describe a cylinder as it moves; it is also easy to do the same thing with the forefinger of the left hand; and it is equally easy