Counterspeech is communication that tries to counteract potential harm brought about by other speech. Theoretical interest in counterspeech partly derives from a libertarian ideal – as captured in the claim that the solution to bad speech is more speech – and partly from a recognition that well-meaning attempts to counteract harm through speech can easily misfire or backfire. Here we survey recent work on the question of what makes counterspeech effective at remedying or preventing harm, in those cases where it (...) is effective, as well as work investigating when and why there is a duty to engage in counterspeech. We suggest that the most fruitful area for philosophical inquiry on this topic, currently, relates to the questions about efficacy. Specifically, we argue that there is a need for better frameworks for conceptualizing the efficacy of counterspeech. Philosophers have collaborative work to do, alongside social scientists, in developing these frameworks. (shrink)