 The sceptic argues that dispositionalist theories face three problems. The first problem—the finitude problem—is that there is a sense in which, much like the totality of our previous linguistic behaviour, our dispositions are finite. Given that the extension of the addition function is infinite, containing a denumerably infinite number of triples \(\langle x, y, z\rangle\) such that x plus y is identical to z, Jones’s meaning addition by ‘+’ cannot be identified with her dispositions to respond to arithmetical queries since it is simply false that she is disposed to answer with the sum when faced with the query ‘\(x + y = \ques\)’. In some (indeed, most) cases, the numbers involved will be so large that Jones’s brain’s capacity for computation is far exceeded, and Jones may even die long before she is able to grasp the relevant numbers. We might follow Boghossian in dubbing such numbers “inaccessible” (2015: 335), and we might define quaddition to be a function that diverges from addition over only inaccessible numbers. In this case, the problem is that, given Jones’s dispositions, it is indeterminate whether he means plus or quus.