Aristotle's contribution to the sum of wisdom dominates all our philosophy and even provides direction for much of our science. And all effective debaters, whether they know it or not, employ Aristotle's 3 basic principles of effective argument that form the spine of Rhetoric: "ethos," the impact of the speaker's character upon the audience; "pathos," the arousing of the emotions; and "logos," the advancement of pertinent arguments. In Poetics, Aristotle observes several aspects of epic poetry, lyric poetry, and comedy, and he draws a dramatic distinction between poetry and history. He maintains that poetry has greater philosophical value because it deals with universals, while history states particular facts. Aristotle's body of work that has come to be identified as Logic includes: classification into 10 categories; proposition; syllogism; and inductive and deductive reasoning.