The central argument of this dissertation is that the origins of the stylistic classification found in ancient rhetorical theory can be discerned already in texts before the time of Theophrastus. The introductory first chapter sets out the ancient concept of style, and argues that Aristophanes' portrayal of poets in the Frogs shows a dichotomy which has much in common with later stylistic classifications. Points of contact between Sophists and those poets are used to suggest that a similar division of orators at the time may have been plausible. The second chapter is an examination of the controversy between Alcidamas and Isocrates. The style of Alcidamas is discussed, particularly in relation to that of his teacher Gorgias. Alcidamas' speech on extemporaneous and written speeches is then compared with the opinions of Isocrates, Plato and Aristotle on different styles of speaking, and it is argued that all four share a common conceptual framework, which has significant points of contact with Aristophanes' stylistic division of poets. The third chapter examines the Contest of Homer and Hesiod, which has long been thought to have been based on an earlier version by Alcidamas. Possible traces of his influence are suggested, particularly in view of his stylistic conflict with Isocrates. The fourth chapter discusses Aristophanes' descriptions of orators. In the light of his criticism of poets (seen in the Introduction) and the rhetorical controversies shown in the second and third chapters, it is argued that he imposes the same basic division on rhetorical as on poetic style. In the Conclusion, after a brief summary of findings and some suggestions of their implications, a new reading of Prodicus' <i>Choice of Herakles</i> is ventured. Using what has been seen of early critical language and imagery, as well as the preferences of second generation Sophists, it is argued that the fable may be viewed as a stylistic allegory, which shows Prodicus' style in contrast with that of Gorgias.