  Expressivism in this form suggests a naturalistic interpretation of practical reason, one that may seem appropriate to the enlightened commitments of the modern scientific world view. It is naturalistic metaphysically, insofar as it makes no commitment to the objective existence in the world of such allegedly questionable entities as values, norms, or reasons for action. If normative and evaluative claims do not represent genuine cognitive achievements, then their legitimacy does not depend on our postulating a realm of normative or evaluative facts to which those claims must be capable of corresponding. It is also naturalistic psychologically, insofar as it yields explanations of intentional human behavior that are basically continuous with explanations of the behavior of non-rational animals. In both the human and the non-human case, behavior is understood as the causal product of noncognitive attitudes, operating in conjunction with a creature’s factual representation of how things are in its environment.  The special sophistication of human agency may be traced to the fact that humans have much more sophisticated linguistic methods for giving voice to their motivating noncognitive attitudes. Indeed, many contemporary expressivists would contend that these expressive resources are sufficiently powerful that we can explain by means of them the features of practical deliberation that initially give it the appearance of a genuine form of reasoning (Blackburn 1998, Gibbard 1990, Gibbard 2003).