Abstract

Undoubtedly, "being" is one of the basic concepts in Plato's philosophy. In this regard, three dialogs of the Republic, Parmenides, and Sophist are of prime importance. In the Republic he speaks of being in relation to the highest good; in Parmenides he speaks of it in relation to the "One"; and, finally, in Sophist he discusses existence in relation to sufism or, in a more exact sense, "non-being".In the Republic, the highest good, which is called the most luminous part of being, grants both "being" and "essence". In Parmenides, an existent which is the outcome of the participation of the "One" in being is the beginning of the infinite number of existents. In Sophist "being" is necessary for the definition of "non-being", and, as a result, necessary for the definition of a sophist.This paper examines the different meanings of "being" in these three dialogs