The wisdom of hindsight and the limits of Humean constructivism

Ordinary normative discourse includes talk about the reasons for action we had in the past but only came to discover in hindsight. In some cases, we come to discover these reasons not because new information has come to light, but because our values have changed. Contemporary metaethical views, namely Street's Humean constructivism and Blackburn's and Gibbard's quasi-realism, have some difficulty accounting for these reasons and the claims we make about them. This difficulty hinges on the diachronic complexity of these reasons and claims. It cannot be the case that these reasons were constructed by the perspective we had in the past before our values changed. If there were no extant reasons in the past, then it would seem that our claims about them in the present cannot be true. Quasi-realists can account for the way in which reason claims purport to be true by appealing to a deflationary sense of truth and so can remain agnostic on the actual existence of these reasons. Nevertheless, Street argues that this agnosticism is inconsistent with the quasi-realists' naturalism that should have them reject the existence of such reasons. I argue that Street would suffer from an even more acute form of this inconsistency were she to account for reasons only discovered in hindsight. At best her view does no better than the view of her chosen rivals. At worst, it discounts reasons that are so central to our moral development that it fails to be plausible.