This paper offers an interpretation of self-Predication (the idea that justice is just) in plato, Given that self-Predication is accepted as obvious both by plato and by his audience, Which entails that "all" self-Predications are clearly, Though not trivially, True. More strongly, It is suggested that "only" self-Predications can be accepted as clearly true by plato. This is to deny that plato had at his disposal an articulated notion of predication, And his middle theory of forms, Primarily the relation of (...) participation, Is seen as his attempt to arrive at that notion. It is argued that his metaphysical and semantical views are heavily influenced by eleatic monism. But this monism is incompatible with the very idea of predication. It is only in his later works, Where he attacks parmenides directly, That plato manages to lay the groundwork for what can be considered as the discovery of predication. (shrink)