This article is a survey of familiar ground—those passages of the Poetics of Aristotle which throw light on the treatment of legend by the tragic poets. Although sweeping generalizations are often made on the use of the traditional stories in drama, our evidence on the subject is slight and inconclusive. We have little knowledge of the form in which most of the legends were known to the Attic playwrights, for the few we find in the Iliad and Odyssey appear there in very different versions from those they take on in the plays, and the fragmentary remains of epic and lyric poetry between Homer and the fifth century B.C. present us with a wide field for speculation, but few certain facts; while vase paintings and other works of art supplement only here and there the scanty information gained from literature.The comments of ancient writers on this aspect of tragedy are surprisingly few, and carry us little farther. The Poetics stands out as the one source from which we can draw any substantial account of the matter. Even Aristotle, of course, is not directly concerned with the history of drama, and deals with it only incidentally in isolated passages; and in considering these it must constantly be borne in mind that he is discussing tragedy as he knew it in the late fourth century, for the benefit of fourth-century readers. But even so, his statements are the main foundation on which our view of the dramatists' use of legend must be built.