  Diodorus' criterion bears some resemblance to the modern concept of strict implication. In particular, it shares some of its disadvantages in that we encounter a parallel to the ‘paradoxes of strict implication’ (Relevance Logic, Lemmon, 153-4). As in Philo's case, no connection of content is required between antecedent and consequent. This time, whenever either the antecedent is impossible or the consequent necessary, the conditional will be true, regardless of whether there is any relevant connection between the two constituent propositions. So for instance ‘If the earth flies, Axiothea philosophizes’ would be true for Diodorus, since the antecedent was considered impossible (DL 7.75). One example given of a Diodorean-true conditional, ‘If it is not the case that there are indivisible elements of things, then there are indivisible elements of things’ (SE, Outlines of Pyrrhonism 2.111), suggests that there was some awareness of these paradoxes in antiquity. In any event, the Stoic Chrysippus developed a system of relevance logic in which neither the ‘paradoxes of material implication’ nor the ‘paradoxes of strict implication’ occur.