This is a draft of my chapter on Agency and Mistakes for the Routledge Handbook of Philosophy of Agency. In it, I focus on performance mistakes and distinguish them from other "derivative" mistakes that we make as agents. I argue that a proper understanding of these mistakes recommends a generalized fallibilism about human agency.

Many have thought that exercises of skill are intentional. The argument of the paper is that this thesis fails to account for important types of mistakes and errors. In what psychologists and linguists call “verbal slips with semantic bias”, a speaker mistakenly switches, reverses, or blends certain conceptual contents. Nevertheless, the speaker has successfully exercised an intellectual skill, insofar as her slip uses concepts in conformity to semantic and logical rules. To flesh out how one might successfully exercise skills without (...) doing so intentionally, the paper appeals to the idea of habit. Verbal slips thus show how human skillfulness has a considerably wider scope than is often supposed. (shrink)