 Van Fraassen is widely (though mistakenly) regarded as holding that the prospect of contrastive underdetermination grounded in such empirical equivalents demands that we restrict our epistemic ambitions for the scientific enterprise itself. His constructive empiricism holds that the aim of science is not to find true theories, but only theories that are empirically adequate: that is, theories whose claims about observable phenomena are all true. Since the empirical adequacy of a theory is not threatened by the existence of another that is empirically equivalent to it, fulfilling this aim has nothing to fear from the possibility of such empirical equivalents. In reply, many critics have suggested that van Fraassen gives no reasons for restricting belief to empirical adequacy that could not also be used to argue for suspending our belief in the future empirical adequacy of our best present theories: of course there could be empirical equivalents to our best theories, but there could also be theories equally well-supported by all the evidence up to the present which diverge in their predictions about observables in future cases not yet tested. This challenge seems to miss the point of Van Fraassen’s epistemic voluntarism: his claim is that we should believe no more but also no less than we need to make sense of and take full advantage of our scientific theories, and a commitment to the empirical adequacy of our theories, he suggests, is the least we can get away with in this regard. Of course it is true that we are running some epistemic risk in believing in even the full empirical adequacy of our present theories, but the risk is considerably less than what we assume in believing in their truth, it is the minimum we need to take full advantage of the fruits of our scientific labors, and, he famously suggests, “it is not an epistemic principle that one might as well hang for a sheep as a lamb” (1980, 72). 