Καὶ Μέλισσος δὲ τὸ ἀγένητον τοῦ ὄντος ἔδειξε τῷ κοινῷ τούτῳ χρησάμενος ἀξιώματι. γράφει δὲ οὕτως· “ἀεὶ ἦν ὅ τι ἦν καὶ ἀεὶ ἔσται. εἰ γὰρ ἐγένετο, ἀναγκαῖόν ἐστι πρὶν γενέσθαι εἶναι μηδέν. † εἰ τύχοι νῦν μηδὲν ἦν, οὐδαμὰ ἂν γένοιτο οὐδὲν ἐκ μηδενός.” [Melissus, fr.  B 1]
[Simplicius, In Aristotelis Physicorum Libros Commentarium 162.23-26]

Melissus also demonstrated the ungenerability of what is by using this common principle. He writes as follows: “What was, always was, and always will be. For if it came to be, it is necessary that before it came to be there was nothing. Now if there was nothing, in no way could anything come to be from nothing.” (tr. Pamela Huby & Christopher Charles Whiston Taylor)