  At the time of Diodorus and Philo a distinction between simple and non-simple propositions was in circulation among the minor Greek Socratic philosophical sects (DL 2.139). Simple propositions were divided into affirmations and negations (ibid.). Among non-simple propositions, which were thought to be composed of simple ones, conditionals, disjunctions and conjunctions were distinguished. Disjunctions or conditionals featured as premises in many of the logical paradoxes and sophisms which members of the Dialectical school discussed. It is likely that Diodorus and Philo examined the truth-conditions of all three kinds of non-simple propositions; however, we know their views only for the case of the conditional (see below sect. 3).