  Philo's criterion for the truth of a conditional is truth-functional. Later in antiquity, it was generally accepted as a minimal condition for the truth of a conditional. Philo maintained that a conditional is false when and only when its antecedent is true and its consequent false, and true in the three remaining cases: whenever the antecedent is false, and when both antecedent and consequent are true (SE, Against the Logicians 2.113-114). Thus this notion of a conditional comes very close to that of modern material implication. (It is not the same, since truth for Hellenistic philosophers is relativized to times.) Philo's suggestion is remarkable in that it deviates noticeably from the ordinary language understanding of conditional sentences and requires abstraction on the basis of a concept of truth-functionality.