This physical isomorphism approach faces indeterminacy problems. Any given structure in the brain is going to be causally related to, and isomorphic in various respects to, many different structures in external reality. But we cannot discriminate the one it is intended to represent, or that it is supposed to be true “of.” These locutions are heavy with just the intentionality that eliminativism denies itself. Here is a problem of underdetermination or holism that eliminativism shares with intentionality-dependent theories of mind. Here, we can only invoke pragmatic criteria for discriminating successful structural representations —the substitute for true ones, from unsuccessful ones—the ones we previously would call the false ones.