For the reader who considers economic theory of choice as a special case of a more general theory of action, Hume's discussion of the determinants of action in the Treatise of Human Nature (1739-1740), in the Enquiry on Human Understanding (1748), and in the Dissertation on Passions (1757), deserves attention. However, according to some modern commentators, Hume does not seem to have given any evidence which would favour what we nowadays consider as the kind of rationality involved in modern theories of rational choice. On the contrary, this paper arrives to the conclusion that consistency between preferences and choice, like the usual properties of completeness and transitivity, may be considered as outcomes of a mental process, described by means of a decision algorithm which aims at representing Hume's theory of choice.