“νόμωι (γάρ φησι) γλυκὺ καὶ νόμωι πικρόν, νόμωι θερμόν, νόμωι ψυχρόν, νόμωι χροιή, ἐτεῆι δὲ ἄτομα καὶ κενόν (Tetralogies of Thrasyllus, 9; Sext. Emp. adv. math. VII 135) Sweet exists by convention, bitter by convention, colour by convention; atoms and Void [alone] exist in reality. (trans. Freeman 1948), p. 92.”