A useful summary of ethical and other philosophical issues raised by rhetoric can be found in E. Garver, ‘Rhetoric’, in E. Craig (ed.), Routledge Encyclopaedia of Philosophy 8 (London: 1998), pp. 305-310. K. J. Dover, Greek Popular Morality in the Time of Plato and Aristotle (Oxford: 1974; repr. Indianapolis: 1994) is a rich study of rhetoric, along with comedy, as evidence for the ethics of the surrounding society. S. Usher, Greek Oratory: Tradition and Originality (Oxford: 1999) forms a good complement to this, with illuminating detailed studies of many speeches, including those of Isocrates. Three useful, approachable and influential studies of the development of Greek rhetoric are T. Cole, The Origins of Rhetoric in Ancient Greece (Baltimore: 1991), G. A. Kennedy, A New History of Classical Rhetoric (Princeton: 1994), and E. Schiappa, The Beginnings of Rhetorical Theory in Classical Greece (New Haven: 1999). These all contain material about ethical issues, as well as providing general background. Finally, two books that may be recommended which focus respectively on Plato’s and Aristotle’s writings on rhetoric are R. B. Rutherford, The Art of Plato (London: 1995) and A. E. Rorty (ed.), Essays on Aristotle’s Rhetoric (Berkeley and Los Angeles: 1996). Rutherford includes detailed studies on Plato’s Gorgias and Phaedrus among other relevant dialogues, while the Rorty volume includes an excellent selection of essays on ethical topics within Aristotle’s Rhetoric. The following are good translations of some key Greek texts: J. Dillon and T. Gergel, The Greek Sophists, Penguin Classics (London: 2003), J. Henderson, Aristophanes, Loeb Classical Library, 3 vols. (Cambridge, MA: 1998), G. Norlin and L. van Hook, Isocrates, 3 vols. (Cambridge, MA: 1928-45), and especially D. C. Mirhady and Y. L. Too, Isocrates 1 (Austin: 2000) and T. L. Papillon, Isocrates 2 (Austin: 2004).