It is not immediately apparent that new structure leads to new content, that is, that discerning the underlying musical scale of the dialogues will shit ideas about Plato's philosophy. The argument of this chapter is novel and requires some historical context, but has rich dividends.

Aristotle's signature doctrine that “virtue is a mean” has been at the core of the recent revival of virtue ethics. This chapter uses stichometric measurements in a new way to confirm the minority view that Aristotle's doctrine was already present in Plato.

The question below is whether passages ostensibly about one subject may be read as symbols or allusions to something else. This is not a question amenable to logical demonstration. Methodologically, this section employs a mode of interpretation, commonly used in studies of symbolic or allegorical texts, which relies centrally on an argument from coherence: close readings, comparisons and historical context are combined to elucidate the secondary referents of allusive passages. The conclusions reached, however, are strong and the last section below will be devoted to a retrospective analysis of the arguments.

This chapter is part of a larger project that compares passages at the same relative location in different dialogues. A surprising number of themes are shared by these parallel passages (Chs 3, 6).

Aristotle on virtues and means

One strand of scholarship on Aristotle's doctrine that virtue is a mean interprets it as a borrowing from Plato and ethical discussions in the Academy, implying that Aristotle elaborates a doctrine only alluded to in Plato.