 However, Plato’s interest in technê is not innocent. He uses the notion as a way of explicating central themes, such as virtue, ruling, and the creation of the cosmos. As a consequence, he develops a complex account of technê. First of all, a craft has a function (ergon); this is what it characteristically does or what it characteristically accomplishes. In fact, crafts are differentiated by their specific functions (erga)(Rep. 346a). A similar idea is assumed in the exchange between Dionysiodorus and Socrates (Euthydemus 301c), as it is by Socrates in Euthyphro (13d) and Ion (537c). While the ergon of a craft is its goal, the goal is frequently identified with a result separate from the activity of the craft. In the Euthydemus (291e) the goal (ergon) of medicine is health just as food is the goal (ergon) of farming. When in the Charmides (165e) Critias denies that calculation has an ergon, in the way that a house is the ergon of building or a garment of weaving, Socrates answers that nevertheless calculation is about the odd and the even. His answer suggests the possibility of a technê whose goal is not a separate result — an idea to be found in the Statesman. Still in the Gorgias (453e–454a) Socrates argues that calculation produces as its ergon persuasion about the amount of the odd and the even — a result separate from the activity of calculation.