 Why bother to build such a theory? There are many possible answers, and Grice would no doubt have given more than one, but we focus on just one answer, which is implicit in this work. Recall that, on his view, commonsense psychology consists, at least in part, of a body of self-justifying descriptive, explanatory, and evaluative principles. The principles are ‘self-justifying’ in the sense explained earlier in section 6. An illuminating description of these principles would be an illuminating description of how we think, and such a description would certainly be of interest. How do we get one? By carefully examining what we say. Two tenets of ordinary language philosophy were that a clear view of what we mean in the language we use is a clear view of what we think, and that a necessary step in getting clear view of what we mean is close attention to the details of what we say. But the detailed examination will only reveal what we mean if we can reliably distinguish between “the case in which an utterance is false or fails to be true, or more generally fails to correspond to the world in some favored way, and the case in which it is inappropriate for reasons of a different kind.” 