 Galen also rejected Stoic propositional logic and instead embraced a hypothetical syllogistic which was strongly influenced by the Peripatetics and based on elements of Aristotelian logic.One of Galen's major works, "On the Doctrines of Hippocrates and Plato", sought to demonstrate the unity of the two subjects and their views.Using their theories, combined with Aristotle's, Galen developed a tripartite soul consisting of similar aspects.