Is volitional conceptual change feasible? Answering that question requires a theory of semantic change, which is sometimes thought elusive. Fortunately, much is known about semantic change as it occurs in the wild. While usage is chaotic and complex, changes in a word’s use can produce changes in its meaning. There are several under-appreciated empirical constraints on how meanings change that stem from the following observation: word use finely reflects equilibrium between various communicative pressures. Much of the relevant work in linguistics (...) has employed the methods of empirical pragmatics and diachronic semantics. In this way, the study of meaning change can be brought to bear on the conceptual engineer’s normative project. The picture that emerges tells against the sorts of engineering projects most likely to appeal to philosophers. Some may stand to succeed, but they have significantly different contours than the typical ones. (shrink)