24 HISTORY OF SCIENCE. 



ing them as in chariots. He showed them that each must be received 

 into a body, and that the soul which had lived righteously during its 

 appointed time would return to the habitation of his star. But if he 

 failed in doing this, he would in a second generation pass into a woman, 

 "and should he not cease from evil in that condition, he would be 

 changed into some brute who resembled him in his evil ways, and 

 would not cease from toils and transformations until he followed the 

 original principle of sameness and likness within him, and overcame 

 by the help of reason the latter accretions of turbulent and irrational 

 elements, composed of fire and air, and water and earth, and returned 

 to the form of his first and better nature." 



The divine offspring of the Creator, to whom He had committed 

 the task of forming mortals, having received at His hands the im- 

 mortal principle of the soul, constructed for it a mortal body, the 

 materials of whSch they borrowed from the fire, air, earth, and water 

 of the world. These they joined in not indissoluble union, for the 

 elements were to be restored to their original forms. For the re- 

 ception of the more divine and immortal principle they prepared the 

 head, making its shape round in imitation of the spherical form of the 

 universe. The rest of the body was formed to serve the head, to bear 

 it aloft, and carry it honourably and safely about the earth. In the 

 head they placed organs by which the soul might perceive. The 

 gods formed within the body a soul of an inferior and mortal nature, 

 and this they placed in the breast, divided from the habitation of the 

 higher principle by the narrow isthmus of the neck. The dwelling- 

 place of the inferior soul was itself partitioned by the midriff. The 

 space between this and the neck was the seat of the emotional or 

 irascible part of the mortal soul ; while below the midriff was seated 

 that part of the mortal soul which is concerned with the bodily 

 appetites. This position the gods assigned **o the lowest creature, 

 in order that his habitation might be as far away as possible from the 

 head, where, as in a council-chamber, the higher principle might, 

 removed from all disturbance, consider calmly what was best for the 

 whole. In order to awe and restrain the turbulence of this lower 

 nature, the gods made the liver to dwell with it, and made this com- 

 pact, bright, smooth, and bitter. The liver was made smooth and 

 bright " in order that the power of thought, which originates in the 

 mind, might be reflected as in a mirror, which receives and gives back 

 images to the sight." The spleen is for the purpose of keeping the 

 liver bright and clear ; it acts like a sponge for cleaning the mirror. 

 In the same strain, Plato points out the design of other parts of the 

 body. The flesh, for instance, is merely a sort of padding, for it was 

 intended, he says, as a protection against heat and cold and falls. 

 He discusses the causes of diseases, which he attributes to a reversal 

 of the natural order in which the structural elements of the body pass 

 one into another. He supposes that sensations and movements are 



