No less interpretively challenging is the material concerning the other main areas of Galen’s contribution, those relating to hypothetical logic and to the “relational syllogism”. The subject again resists non-specialist summary; but it seems uncontroversial, at least, (a) that Galen engages in detail with Stoic hypothetical syllogistic; (b) that he attacks the Stoics for particular aspects of their use of it; and (c) that this attack is in some way related to his own insistence on the priority of “things” over “expressions” (a motto which runs through much of Galen’s other work, too, in the context of discussions of language). A final area of complexity and doubt concerns the relational syllogism, the introduction of which Galen claims as his innovation at Inst. Log. 16. What seems clear is that Galen brought this new type of syllogism forward in response to what he perceived as inadequacies in both Aristotelian and Stoic logic; also that he believed it to be of particular relevance for proofs in geometry and mathematics. An example of a relational syllogism—from which such relevance is indeed clear—is: