The grounds for critique offered by Roy Bhaskar have developed over the course of his work, but two claims have remained central: ethical naturalism and moral realism. I argue that neither of these is compatible with a scientific realist understanding of values: a scientific realist approach commits one to treating values as socially produced and historically contingent. This does not, however, prevent us from reasoning about values, nor from developing critiques by combining ethical reasoning with a theoretical understanding of the (...) social world and its possibilities. In particular, we can draw on a variety of Habermas's discourse ethics to offer provisional justifications for value-claims that support a critical stance. Thus we can develop grounds for critique that are both ontologically credible and anti-foundational, but also judgementally rational. (shrink)