  Why, anyway, would the Platonist of the Republic think that examples of the objects of knowledge are enough for a definition of knowledge? He is surely the last person to think that. The person who will think this is the empiricist, who thinks that we acquire all our concepts by exposure to examples of their application: Locke, Essay II.1, Aristotle, Posterior Analytics 100a4–9. For the Platonist, definition by examples is never even possible; for the empiricist, definition by examples is the natural method in every case. This suggests that empiricism is a principal target of the argument of the Theaetetus. More about this in sections 6–8.