It is hard even to imagine a conception of trust that is nonreductive and still plausible. One might argue that joy is conceptually not reductive, although it is probably causally explicable in reductive terms. Trust is not merely an unvarnished emotion, however, in the sense that joy is. Emotions might come into particular trust relationships, but trust is not itself simply an emotion.

DEFINE: Distinguishes trust from a mere emotion by arguing trust cannot be reductively explained, even though joy potentially can.

Russell Hardin, Trust and Trustworthiness, loc. 299