  That next move starts with Socrates securing Hermogenes’ rejection of out-and-out relativism like that of Protagoras. (See the entry   Plato on knowledge in the Theaetetus.)   This in turn commits him to the view that things have objective natures independent of how they may appear to us, and that there are objectively determined skills for dealing with them: for example, the right way to cut something is determined, independently of our own subjective preferences, by that thing’s objective nature. Like cutting, naming too will be an objective science. Much as a shuttle is a tool for separating threads, a name is a ‘tool for instructing by separating being’ (388a–c). But tools must be made by appropriate experts, who are themselves advised and guided by the tools’ destined users. Thus, just as the shuttle-making carpenter is guided by the weaver who has commissioned his product, so too the name-maker is an expert who, ideally at least, is guided by that ultimate expert in word use, the dialectician. It follows that names, if correctly made, cannot be randomly adopted, as Hermogenes’ conventionalism would imply, but on the contrary need to be expertly made for their specific purpose, in a way that corresponds to the natures of the things they name.