It is often thought that Plato sets himself an important task in the Sophist – that of disentangling different uses, or senses, of the verb einai. Plato is thought to have confused different senses or uses of the verb in his philosophical youth; here he is supposed to correct his mistake, and to mark out a danger area for his successors.1 Plato is also often supposed, by commentators, to have set himself the task of disentangling a second confusion – a (...) confusion between the mē on and the mēdamōs on : on this view, the mē on is revealed as the negation of the on, whereas the mēdamōs on is the opposite of the on. (shrink)