This chapter is about sensibility, which is the term that was commonly used in the second half of the eighteenth century to refer to a special capacity to respond with sensitivity to one’s environment. Colloquially understood as the heightened responsiveness of feeling or emotion, sensibility – in cultural, literary, artistic, historical, social, philosophical, and political contexts – reached far beyond what either of these more familiar terms convey. Eighteenth-century thinking about sensibility, in all of its complexity, remains deeply relevant to twenty-first century theories of affect, feeling, and emotion, and provides robust resources for, and in some cases correctives to, current theoretical and philosophical thought.