MELISSUS, a philosopher of the Eleatic school, was born in Samos, and flourished about 444 B.C. He took a very active part in the political struggles of his country, and his fellow-citizens honoured him on one occasion with the command of a naval armament. Little more is known respecting his life. Like almost all the philosophers of this epoch of Greek speculation, he composed a treatise on "Being and Nature" (περὶ φύσεως). He raised a vigorous protest against the empirical sensualism of the Ionic philosophers, among whom he spent his life in his native island. His master, Parmenides, maintained that the senses could furnish nothing certain, and that the study of being, essentially and absolutely one and immovable, was the only occupation worthy of a philosopher. Zeno, again, had proved to the Ionians that to admit matter is to admit divisibility, which is the condition of extension; but being is indivisible, and hence matter has only a phenomenal existence. Such was the position of antagonism of the two schools when Melissus appeared. He attempted to enlarge the basis of the Eleatic school by borrowing the notions of time and space admitted by the Ionians, but ignored by Parmenides. Having pronounced being to be infinite and one, Melissus applied the same quality to time and space, which led him to their identification. Nothing relative, according to him, can be eternal; motion is impossible, for being is infinite, and motion requires a void. Aristotle (Met. i. 8) accuses Melissus of confounding being with matter, but places him higher than Parmenides as a philosopher. As for the existence of the gods, Melissus, like the rest of his school after the time of Xenophanes, declared that it was impossible to arrive at any certainty. Melissus was the last representative of the Eleatic doctrines. (See the Fragments of Melissus, collected by Brandis, Comment. Eleat., Copenhagen, 1813.)