looked on the forces of nature, as powerful and helpful, but when it was still quite helpless to guide or control them to any great extent for its own purposes.
However, there was in the muscular system even of the human body something very different to this system of "laissez-faire." "After a bone has been moved by a muscle," says the elementary physiology book, "it is brought back to its former position by the action of a second muscle on its opposite side." Hence we find that muscles are generally arranged in pairs, each muscle of a pair being antagonistic in its action to the other. Rouleaux, the great authority on mechanics, says that the present day ideal of the great mechanic is to advance from force-closure to pair-closure. In force-closure, as we have seen, the forces of nature are used to stop some movement of a machine, but in pair-closure the machine itself can stop itself—like a moral person! The ideal of the mechanic, as well as of the saint, is self-control. This ideal then which is being slowly realized by the mechanic, and more slowly yet by all civilized men in the moral sphere, had yet been for ages illustrated in every part of the muscular system.
Why (since it is the open secret of the muscular system) was not this ideal realized quickly in machinery? All kinds of reasons may be given, but
