Abstract
Barry Allen, drawing on Wittgenstein's standard-metre example from Philosophical Investigations, argues there can be no determinate similarities or differences in the absence of a practice of measuring such similarities or differences. I contend that one can accept Allen's premises without accepting his conclusion if we draw a distinction between being and being true of the following sort: although it was not true, in the absence human or other epistemic practices, that water was H2O, nonetheless, before there were any human or other epistemic practices, water was H2O. This, I argue, is compatible with retaining the truism that it is true that p if and only if p, and it allows us to avoid the idealism of Allen's conclusion.