* Earlier versions of this paper were presented at the annual conference of the Classical Association (Birmingham, 14 April 2007), and at Columbia University (26 October 2007). I am grateful to both audiences for their very helpful comments and suggestions, and especially to Andrew Barker, Susanna Braund, Kathleen Coleman, Maggi Creese, Joshua T. Katz, Lindsay A. Mann, C.W. Marshall, Hallie Rebecca Marshall, Ian Runacres, Elizabeth Scharffenberger, James Uden and R.J.A. Wilson. I wish to thank the journal's anonymous referee for suggesting a number of welcome improvements.