Very often dervishes and fakirs in the East, many of whom live upon alms and go several days without food and spend many nights in sleepless vigil, do things which are difficult for a wrestler, a boxer, or any other muscular person. Some dervishes practice jumping into fire, standing for hours in the water, sitting or lying on iron pricks, thrashing their bare arms and legs, cutting themselves with knives and swords, and all such things, beyond the power of a physically strong man. Often a physically strong man suffers in proportion to his strength when he is exposed to pain or torture.