The thought of Wilfrid Sellars has figured prominently in recent discussions of the relationship between naturalism and normativity . On the one hand, some have appealed to Sellars' philosophy in defence of the thesis that what he called the normative 'space of reasons' is in some sense sui generis and irreducible to the natural causal order described by the natural sciences. On the other hand, others have exploited equally central aspects of Sellars' philosophy in defence of the seemingly incompatible project (...) of attempting to give an exhaustive scientifically naturalist account of mind and meaning, and perhaps of the nature of normativity itself. I contend that what Sellars described as 'the Janus-faced character of languagings as belonging to both the causal order and the order of reasons' ( Naturalism and Ontology ) is the key to understanding his normative and pragmatist variety of naturalism. Sellars saw himself as having articulated a detailed philosophical perspective within which the normative aspects of meaning, knowledge, truth, and representation are themselves opened up, in principle, to naturalistic explanation. (shrink)