Walter Pater’s theoretical ‘come-back’ over the past forty years or so has been dominated by the competing claims of the new historicism and deconstruction, both of which discover prescient forerunners of their own, seemingly mutually exclusive, theoretical concerns in Pater’s aesthetic criticism and historical novel, Marius the Epicurean. Yet despite their obvious differences, both critical approaches share one thing in common: the same post-humanist denigration of the trope of metaphor in favor of the seemingly more ethically responsive, because inclusive, trope of metonymy. In this essay, I observe how the new historicism’s and deconstruction’s privileging of this latter figure as the prime trope of difference poses an immediate problem for ethical thought that, largely under the influence of Alain Badiou, has become increasingly cognizant of the need for a workable conception of sameness (or universality), traditionally supplied by metaphor. Accordingly, this close reading of the metaphorical dialectic of one of Pater’s surprisingly under-read Imaginary Portraits, “Sebastian van Storck”, explores the basic charge against metaphor, namely, that it is an essentially ‘theological’ trope insofar as it invariably pre-posits the “identity” it modestly claims to have merely discovered. Employing the central figure of Sebastian’s idealism – equation – I venture that, once rethought as a relation not of identity but of equivalence, metaphor is capable of shouldering the rhetorical burden of similarity without relinquishing its ethical claim as a primary producer of new differences in the world and is, hence, deserving of a central place in a post-deconstructive ethics.