AbstractPartial reasons are considerations in favor of something that, taken individually, are not sufficient to establish an obligation. I consider the extent to which partial reasons are reasons, and why they cannot be reduced to or identified with pro tanto reasons. I lay out two approaches to the content of reasons, the flat theory and the structured theory. I argue that parts of reasons are not partial reasons, by showing that natural ways to represent parts of reasons in the flat theory and the structured theory lead to overgeneration problems with regard to partial reasons. I then formulate two notions of partial reasons: one based on a notion of partial support, which is in turn captured by the notions of full support and partial content, and one based on the notion of in exact verification. I show under which conditions the two notions of partial reasons (based on partial content, and based on inexact verification) coincide.