On Automata, or Self-Moving Machines

sought in those machines by which the greatest weights are raised, and upon which depend the most powerful effects of those by which the walls of fortresses and cities are attacked and defended. All these are subordinate to Mathematics, because, although the subject matter is physical, they are demonstrated by force of mathematical reasons: wherefore they are mathematical as far as the demonstration is concerned, and natural in what pertains to the subject, as the Philosopher taught very well in the Posterior Analytics and at the beginning of the Mechanics.

We, having set aside the other subordinate sciences, shall treat of Mechanics; and of these we shall not embrace the entire genus, but shall discourse only upon that part of it which extends to Self-moving Machines. The Greeks gave these the names of Automata, Automatopoetics, and Autocineta, which signifies as much as if one were to say "spontaneous"—that is, things which operate and move of themselves; and of this nature are those of Hero which we translate, as well as those which, by means of counterweights, divide time for us. It is to be believed that the first inventors of these devices set before their eyes that natural and internal propensity which heavy bodies have to descend toward the center of themselves—that is, without need of external aid—and from this they imagined they could, by means of them, give motion to some other thing, since upon this alone depends the whole force of these contrivances; or else they fixed their minds, as it seems the Philosopher holds at the beginning of his Mechanics, upon the marvelous nature of the circle. In Sacred History, I do not recall mention being made of anything by which it might be affirmed that in those most ancient times this art had been discovered; for although one reads of that most ancient inventor of the art of iron and of his greatest industry, one does not, however, find