The phenomenon of silencing has taken on new salience in the wake of #metoo and controversies around free speech. Using tools from the social philosophy of language, Mary Kate McGowan's On Silencing explains, in an accessible way, what silencing is and why it is important. Understanding silencing as a failure of communication, McGowan shows how communication can fail in one of three ways: one can be prevented from speaking, a speaker can be misunderstood, and a speaker can be understood but not affect the world as one should (such as when orders are not followed, refusals are not respected, and assertions are not believed). McGowan also explains how silencing is more likely to happen when we are trying to communicate across difference, and she provides concrete suggestions for what we can do--both as speakers and as hearers--to avoid contributing to harmful forms of silencing. In addition to explaining a pervasive social phenomenon in an accessible way, On Silencing makes novel contributions to current academic debates about silencing.