Abstract

Standing in San Marco Cathedral in Venice, you immediately notice the exquisitely decorated spandrels: the triangular spaces bounded on either side by adjoining arches and by the dome above. You would be forgiven for seeing them as the starting point from which to understand the surrounding architecture. To do so would, however, be a mistake. It is a similar mistaken inference that evolutionary biologists have been accused of making in assuming a special adaptive purpose for such biological features as fingerprints and chins. I argue that a mistake of just this sort is being made by ethicists who appeal to the intrinsic value of supererogatory acts in their efforts to make space for supererogation in ethical theory. Many cases of supererogatory action are simply spandrels: by-products of uncontroversial commitments elsewhere in our moral thought. This is not to downplay their value but rather to show that their value need not be the justification for making room for the supererogatory. I demonstrate this by examining two areas: rights and the distribution of burdens among a group. My argument has significance for those who take themselves to be defends of the possibility of supererogatory actions, as well as those who are committed to the contrary and those who believe themselves to be indifferent on the matter.