is only the absence. When nothing acts on matter, it does not move; it is equally indifferent to motion and rest; its natural state, therefore, is to be at rest.
Again, I perceive in bodies two kinds of motion; that is, a mechanical or communicated motion, and a spontaneous or voluntary one. In the first case, the moving cause is out of the body moved, and in the last, exists within it. I shall not hence conclude, however, that the motion of a watch, for example, is spontaneous; for if nothing should act upon it but the spring, that spring would not wind itself up again when once down. For the same reason, also, I should as little accede to the spontaneous motion of fluids, nor even to heat itself, the cause of their fluidity.
You will ask me if the motions of animals are spontaneous? I will freely answer, I cannot positively tell, hut analogy speaks in the affirmative. You may ask me further, how I know there is such a thing as spontaneous motion? I answer, because I feel it I will to move toy arm, and, accordingly, it moves without the intervention of any other immediate cause. It is in vain to attempt to reason me out of this sentiment; it is more powerful than any rationed evidence. You might as well attempt to convince me that I do not exist.
If the actions of men are not spontaneous, and there be no such spontaneous action in what passes on earth, we are only the more embarrassed to conceive what is the first cause of all motion. For my part I am so fully persuaded that the natural state of matter is a state of rest, and that it has in itself no principle of activity, that whenever I see a body in motion, I instantly conclude that it is either an animated body
