Context: Aristotle is, of course, the universal critic. In the fields of science, philosophy, morals, and literature he records the wisdom of the Grecian era. In the Poetics he describes tragic drama, the particular type of literature which was most admired in Greece and in the production of which Athenians excelled. Aristotle draws initial distinctions between tragedy and comedy and, in turn, between tragedy and epic poetry in such matters as origin and style. More specifically, he addresses himself to the particular components of the tragic form–plot, character, diction, music, scenic design. The plot, "an imitation of an action that is complete and whole and of a certain magnitude" and the most significant of these components, depicts a noble character involved in a disastrous reversal of fortune resulting from the fatal effects of pride upon his character. Theoretically, the spectators–involved vicariously in the emotion of the scene–are cleansed of pity and fear and thus undergo a spiritually cathartic experience. At one point, Aristotle compares the tragic poet to the historian. Since the dramatist conventionally deals with legendary heroes, both he and the historian are concerned with the re-creation of action from the past; but the object of the historian is the exact reporting of fact, that of the poet the rearrangement of detail for emotional potential:
. . . It is, moreover, evident from what has been said that it is not the function of the poet to relate what has happened but what may happen–what is possible according to the law of probability and necessity. The poet and the historian differ not by writing in verse and in prose. The work of Herodotus might be put into verse, and it would still be a species of history, with meter no less than without it. The true difference is that one relates what has happened, the other what may happen. Poetry, therefore, is a more philosophical and a higher thing than history; for poetry tends to express the universal, history the particular. . . .