For Plato, the crucial function of human cognition is to grasp truths. Explaining how we are able to do this is fundamental to understanding our cognitive powers. Plato addresses this topic from several different angles. In the Cratylus and Theaetetus, he attempts to identify the elemental cognitions that are the foundations of language and knowledge. He considers several candidates for this role, most notably, perception and simple meaning-bearing concepts. In the first section, we will look at Plato’s worries about semantic (...) instability and its epistemic consequences. The central role of basic cognitions in Plato’s account of knowledge in the Theaetetus will be explored in the second section. In the final section, the relevance of Plato’s conception of cognition to modern discussions in the philosophy of language and epistemology will be noted. (shrink)