How do you recognize the voice of your conscience? One possibility is that you recognize this voice by what it talks about – namely, your moral obligations, what you morally ought or ought not to do. Yet if the dictates of conscience were recognizable by their subject matter, you wouldn't need to think of them as issuing from a distinct faculty or in a distinctive voice. You wouldn't need the concept of a conscience, any more than you need concepts of distinct mental faculties for politics or etiquette. Talk of conscience and its dictates would be like talk of the mince-pie syllogism, in that it would needlessly elevate a definable subject matter to the status of a form or faculty of reasoning.

Our having the concept of a conscience suggests, on the contrary, that ordinary practical thought does not contain a distinct, moral sense of ‘ought’ that lends a distinct, moral content to some practical conclusions. The point of talking about the conscience and its voice is precisely to mark a distinction among thoughts that are not initially distinguishable in content. Among the many conclusions we draw about what we ought or ought not to do, some but not others resonate in a particular way that marks them as dictates of conscience. The phrase ‘morally ought’ is a philosophical coinage that introduces a difference of sense where ordinary thought has only a difference of voice – whatever that is.

But what is it? Conscience doesn't literally speak.