The Principle of Motion

The motion according to place islation that according to quality, alliation and that according to quantity increase and diminution. Whatever therefore is born along is either moved by itself or by another. In these it is evident that in these the mover and the thing moved subsists together. For impulsion is a certain pushing since that which pushes anything from itself follows the thing which it pushes. But repulsion is when the mover does not follow by moving.