Leucippus

The principle of sufficient reason goes back at least to the world’s first atomist, Leucippus, who (if he existed!) predated the better- known atomist Democritus (c. 460 – c. 370 BC). The only surviving fragment from Leucippus is “οὐδὲν χρῆμα μάτηῳ γίνεται, ἀλλὰ πάντα ἐκ λόγου τε καὶ ὑπ’ ἀνάγκης” (“Nothing occurs at random, but everything for a reason and by necessity.”; Kirk and Raven 1957, p. 413; see also Landsman 2018).