A state in which all one’s thoughts about a topic fit together; in which there are no loose ends or recalcitrant elements that do not cohere with an overall position. The term is associated with Goodman, and gained currency from the work of Rawls, who suggested that the proper method of ethics should be one of trying to achieve reflective equilibrium, testing theories against judgements about particular cases, but also testing judgements about particular cases against theories, until equilibrium is achieved. The worry is that there can be different point of equilibrium, some of which may be fairily undesirable, depending on where you start. See also coherence theory of truth, Neurath’s boat.