 The difference between the philosophical approach of the Republic and that of the Timaeus lies in the fact that Plato concerns himself in the later dialogue with the structure of the visible heaven as a model for the human soul, and also with the material conditions of human physiology. What is confined to mythology in Plato’s earlier works is here worked out – though not without the caveat to the effect that Plato is merely offering a likely account of the structure of the universe, of the human soul, and of human physiology – rather than proven facts. Plato’s choice of presenting his explanation of the order of the universe as a story of creation by a ‘divine workman’ is certainly no accident. It can be understood as a kind of ‘retractation’ of his deprecatory statement concerning the divine workman’s product that appears in the Republic, where this product is denigrated because of its inferiority to a purely theoretical model. To be sure, the Timaeus presupposes the Forms as the divine workman’s unchanging models (27d–29d; 30c–31b) and resorts to mathematical principles to explain the cosmic order, but the focus is almost exclusively on the construction of the visible heavens. Plato now seems convinced that in order to explain the nature of a living being, it is necessary to show what factors constitute such a live organism. 