              Aristotle regards rhetoric and the arts as belonging to the productive sciences. As a family, these differ from the practical sciences of ethics and politics, which concern human conduct, and from the theoretical sciences, which aim at truth for its own sake.  Because they are concerned with the creation of human products broadly conceived, the productive sciences include activities with obvious, artefactual products like ships and buildings, but also agriculture and medicine, and even, more nebulously, rhetoric, which aims at the production of persuasive speech (Rhet. 1355b26; cf. Top. 149b5), and tragedy, which aims at the production of edifying drama (Poet. 1448b16–17).   If we bear in mind that Aristotle approaches all these activities within the broader context of his teleological explanatory framework, then at least some of the highly polemicized interpretative difficulties which have grown up around his works in this area, particularly the Poetics, may be sharply delimited. 