To many the healing force developed by Christian Science seems a mystery, because they do not understand that Spirit controls body. They acknowledge the existence of mortal mind, but believe it to reside in the brain; but that man is the idea of Infinite Mind is an opinion not so easily accepted, because mortal mind is hampered by its material beliefs. That which never existed seems a solid substance to the common estimate. It is much easier for people to believe that the body affects Mind, than that the body is an expression of Mind, and reflects harmony or discord, according to thought.