Economic Theory normally assumes the so-called homo economicus, a consequential model of rationality. We highlight the main features of this model in opposition to deontology: axiological homogeneity, maximization and agent neutrality. Amartya Sen’s criticism of standard consequentialism copes to those features, and includes commitment and duty in the economic rationality. We analyze his concept of preference to ascertain how far economic rationality can thus go in the direction of deontology. We conclude that, though diminished, the difference between them still remains.