 Plato was the first to be aware of the demonstrative methods and to distinguish them from the dialectical, sophistical, rhetorical, and poetical methods. But from his point of view they were distinguished in use and according to matter, and in terms of what guidance he received from his considerations at leisure and his superior natural intelligence. He didn’t prescribe universal rules for them. Afterwards Aristotle did prescribe such rules in his book Posterior Analytics. ([Rhetoric] 55.13–17)