How Do Reasons Accrue?

Reasons can interact in a variety of ways to determine what we ought to do or believe. And there can be cases where two reasons to do an act or have a belief are individually worse than a reason to not do that act or have that belief, but the reasons together are better than the reason to not do that act or have that belief. So the reasons together―which we can call the accrual of those reasons—can have a strength that is an increasing function of the strengths of the individual reasons. In this paper, we will look at how reasons determine what we ought to do and believe in cases where the accrual of reasons is relevant. Our focus will not primarily be on questions about the nature of individual reasons and their weight. Instead, we will at the outset rely on our pretheoretical grip on what reasons there are and how weighty they are individually and ask the more formal or structural question of how to determine the strength of their accrual based on these facts. In looking at these issues, my goal will not be anything as ambitious as developing a full theory of the accrual of reasons. Rather, my goal will be more modest: I will introducing some of the challenges for providing an adequate model and argue that a promising approach to resolving these challenges involves making use of the familiar distinction in moral philosophy between derivative and non-derivative normative notions.