 What determines the ‘use’ of a human being, and to what extent can there be a common principle that accounts for all good things? In the Republic, this question is answered only indirectly through the isomorphism of the just state and soul as a harmonious internal order. The postulate of such an orderly structure is not explicitly extended beyond the state and the soul. In contrast, in the later dialogues, the Good clearly operates on a cosmic scale. That such is Plato’s view comes to the fore in his excursus on the philosopher’s nature in the Theaetetus (173c–177c). Contrary to Socrates’ denial in the Apology, Socrates in the Theaetetus affirms that the philosopher is to pursue both what lies below the earth and the heights above the heaven (173e): “tracking down by every path the entire nature of each whole among the things that are.” And Socrates also concerns himself with the question of “What is man? What actions and passions properly belong to human nature and distinguish it from all other beings?” In that connection he compares the discovery of the true nature of things with ‘likening oneself to God’ (homoiôsis theôi) and indicates that there is a unitary principle of goodness. The ability to achieve this superhuman state depends on one’s readiness to engage in strenuous philosophical discourse (177b).