10 Note that I am not denying that A and B differ in baldness. I just claim that it is indeterminate whether they differ in baldness. One might object, however, that if it is false that A is bald and not false that B is bald, then B is balder than A and hence A and B differ in baldness. This reasoning seems to rely on the following principle posited by Carlson, E., ‘Vagueness, Incomparability, and the Collapsing Principle’, Ethical Theory and Moral Practice 16 (2013), pp. 449–63CrossRefGoogle Scholar, at 454:
The monadic collapsing principle. For any x and y, if it is false that y is F, and not false that x is F, then it is true that x is Fer than y.
But this principle is open to counterexamples that are very similar to those offered against the original collapsing principle. Carlson, ‘Vagueness’, pp. 454–5, offers the following:
Let us slightly modify Gustafsson's cavalier case, and assume that B is definitely bald, whereas A is a borderline case of baldness. In all other relevant respects, the two cavaliers are identical. Suppose also that, given their other properties, not being bald is necessary and sufficient for A or B to qualify as a good cavalier. It is thus false that B is good, and indeterminate whether A is good. The monadic collapsing principle then implies that A is definitely better than B. But this seems false, since it is indeterminate whether A lacks the property, viz. baldness, whose absence would constitute the only relevant difference, as compared to B.
Hence it seems question-begging to rely on the monadic collapsing principle in a defence of the original collapsing principle from counterexamples of this type. One might object that, instead of relying on the monadic collapsing principle, one could reason as follows: if it is false that A is bald and not false that B is bald, A must have more hair than B; and if so, B must be balder than A. Yet a problem with this objection is that to be balder is not just to have less hair – the proportion of the scalp covered by hair, for example, also matters. And the relative weights these two factors have in contributing to baldness might be indeterminate. Suppose, for instance, that A has less hair than B but, since it is evenly distributed over his scalp, it is false that A is bald. Furthermore, while B has more hair than A, it is unevenly distributed so some parts of his scalp have little hair, which makes it not false that B is bald. But since each of A and B beats the other in one factor that contributes to baldness and the relative weights of these factors are indeterminate, it is indeterminate whether B is balder than A. A referee for this journal suggests another reply, which is to concede that B is balder than A, but to deny that this difference is relevant to which is the better cavalier. That is, one might deny that being less bald is a better-making relation even though not being bald is good making.