Now if the mover is not accidentally but necessarily in motion so that, if it were not in motion, it would not move anything then the mover, in so far as it is in motion, must be moved either with the same kind of motion, or with a different kind either that which is heating, I mean, is itself becoming hot, that which is making healthy becoming healthy, and that which is causing locomotion in process of locomotion, or else that which is making healthy is in process of locomotion, and that which is causing locomotion in process of increase.