Spinoza's PSR as a Principle of Clear and Distinct Representation

It is argued first, that S pinoza's P rinciple of S ufficient R eason ( PSR ) is best seen as an auxiliary premise and not as an axiom of the E thics ; second, that S pinoza held the PSR to be a self‐evident truth that indicates a necessary condition for clearly and distinctly representing the existence or non‐existence of a thing; and third, that this interpretation of S pinoza's PSR explains the near absence of the PSR within the demonstrations of the E thics as well as the importance of the principle in S pinoza's thought.