Pain has two origins: the mind and the body. Sometimes it is caused by the mind and held by the body, and sometimes it is caused by the body and held by the mind. If one were absent or did not partake of the pain suggested by the other part of the being, the pain would not exist, or if it existed it would vanish. The body being the servant of the mind, can never refuse to bear the pain given by the mind, having no free will of its own; it is only the mind that could refuse, if it were trained to do so.