In this paper, I propose a reading of Spinoza’s theory of the eternity of the mind in light of his theory of essence and existence. Opposing in particular recent Platonist readings of this theory, rejecting the dichotomy between formal essence and actual essence, upon which they mostly rely, I argue that Spinoza’s conception of the eternity of the mind must be grasped in terms of different aspects of one and the same existence. I moreover suggest that, for Spinoza, the mind was both sempiternal and eternal, without, however, those two aspects of the mind’s existence being identical.

The philosophical treatise of Melissus of Samos is often maintained to have a strictly deductive argumentative structure. This article attempts to confirm this thesis by establishing that such a structure is instituted beginning from its title and introductory sphragis. Extant paraphrases of Melissus’ treatise are examined and are argued (in line with some previous treatments) to provide a highly illuminating indication that the work began from the hypothesis that something is. Next, an account of how the first verbatim fragment (DK30B1) takes up this prefatory material is given along with a reconstructed text and translation of the title, preface and argument for the sempiternity of what-is.