The Principle of Motion

Man might teach and be at the same time taught might impart health and be made well according to the same health farther still it has been shown that a thing which is movable is moved but this while it is moved is in capacity and not in energy. The like also will take place in everything else the mover of which necessarily has this anonymous hence of that which moves itself one thing moves and the other is moved, yet neither part can so move itself as that each part should be moved by each. It is not necessary that the mover should be moved except by itself according to accident therefore the other will reciprocally move.