Stoics and Sceptics distinguish belief (doxa) from a representationally and functionally similar but sub-doxastic state: passive yielding to appearance. Belief requires active assent to appearances, that is, affirmation of the appearances as true. I trace the roots of this view to Plato's accounts of doxa in the Republic and Theaetetus. In the Republic, eikasia and pistis (imaging and conviction) are distinguished by their objects, appearances versus ordinary objects; in the Theaetetus, perception and doxa are distinguished by their objects, proper perceptibles (...) versus ‘commons’, including being. But underlying these ontological distinctions is a psychological one: the lower mental states are confined to their lower objects because they are passive; the higher mental states have access to higher objects because they result from questioning appearances and making active affirmations about how things are. This doctrine of doxa anticipates both the Hellenistic one and modern accounts of belief as ‘aiming at truth’; it also shows Plato's views of doxa to have more in their favour philosophically and to cohere better with one another than generally thought. (shrink)