  Aristotle displays some hesitation in his discussion of desire and its relation to practical reason in the aetiology of animal action. Some have consequently concluded that his treatment can be regarded as at best inchoate or, worse, as positively befuddled. There seem to be no grounds for any such harsh assessment, however. Equally likely is that Aristotle is simply sensitive to the complexities involved in any approach to the intertwining issues in the philosophy of action. Unlike some later Humeans, he evidently appreciates that the data and phenomena in this domain are unstable, wobbling and retreating at the approach of taxonomizing theory. The antecedents of action, he rightly concludes, involve some sort of faculty of desire; but he is reluctant to conclude that desire is the sole or sufficient faculty implicated in the explanation of purposive behavior. In some way, he concludes, practical reason and imagination have indispensable roles to play as well.