Universality Reduced

Abstract

The universality of critical phenomena is best explained by appeal to the Renormalization Group (RG). Batterman and Morrison, among others, have claimed that this explanation is irreducible. I argue that the RG account is reducible but that the higher-level explanation ought not to be eliminated. I demonstrate that the key assumption on which the explanation relies—the scale invariance of critical systems—can be explained in lower-level terms. However, we should not replace the RG explanation with a bottom-up account; rather, we should acknowledge that the explanation appeals to dependencies that may be traced down to lower levels.