The author shows that in Parmenides' approach, Aristotelian division of being and the truth still does not exist (i.e. being as presence or an object in general, individual or universal; the truth as the value of the judgement), because for the Eleat the word being only means the truth. This word is the name of the truth as a transcendent nature (resp. essence) in general. In his poem, Parmenides, for whom the truth is the only being, praises and describes the existence of the truth (identified with what truly is or with pure being par exellence) in opposition to the multitude of opinions (appearances of the truth and being). Parmenides' poem is the testimony and account of experience (of existence) of the Truth as Being itself and the experience of its normative force as transcendent nature. This Parmenidean 'aletheism' allows us to understand how Plato's theory of eternal truths ever appeared (Ideas, or Forms, as norms and paradigms of nature, cognition, and action), as well as the importance of Parmenides himself for Neoplatonism.