This paper aims to identify the constitutive rule of assertion, conceived by analogy with the rules of a game. That assertion has such rules is by no means obvious; perhaps it is more like a natural phenomenon than it seems. One way to find out is by supposing that it has such rules, in order to see where the hypothesis leads and what it explains. That will be done here. The hypothesis is not perfectly clear, of course, but we have (...) at least a crude conception of constitutive rules, which we may refine as we elaborate the hypothesis. Although no attempt will be made here to define ‘rule’, some remarks on constitutive rules will focus the discussion. (shrink)

Nothing seems to follow strictly from 'X believes that p'. But if we reinterpret it to mean: 'X can consistently be described as consistently believing p'--which roughly renders, I think, Hintikka's notion of "defensibility"--we can get on with the subject, freed from the inhibitions of descriptive adequacy. But defensibility is neither necessary nor sufficient for truth: it tells us little, therefore, about the concept of belief on which it is based. It cannot, in particular, specify necessary conditions for the consistent (...) ascription of belief--as opposed to rational belief. If there are no such conditions, all belief ascriptions must be treated as atomic: which is implausible. If there are some, they must be settled on before an account of consistency can be complete. The reason is simple: it is that we have beliefs about our own beliefs. A set of first order beliefs is consistent if they can all be true together; but it is a lesson of Moore's paradox that consistency of second-order beliefs requires additional constraints. If someone both believes that p and that he does not believe that p, the propositions he believes might all be true together, yet he is inconsistent. And the characterization of second order consistency will remain incomplete, so long as nothing is said about the consistency of first order belief ascriptions. Suppose someone says and believes: "I am inconsistent: I believe both p and ~p." This is "indefensible": but is it insight, or nonsense? Breast-beating of this sort is guaranteed success: something he believes is bound to be false. But that remains diagnostically frustrating: is he inconsistent because what he said is true, or on the contrary because it is inconsistent? (shrink)