  Traditionally, many philosophers thought that such a solution was downright incoherent. A tradition stretching back to Bertrand Russell (1923) and Michael Dummett (1975) held that vagueness was always and everywhere a representational phenomenon. From this perspective, it didn't make sense to talk about it being vague or indeterminate whether a particular droplet was part of a particular cloud. But this traditional view has come under a lot of pressure in recent years; see Barnes (2010) for one of the best challenges, and Sorensen (2013, section 8) for a survey of more work. So I'll assume here it is legitimate to talk about the possibility that parthood itself, and not just our representation of it, is vague.  As Hudson (2001) notes though, it is far from clear just how the appeal to fuzzy logic is meant to help here. Originally it was clear for each of n water droplets whether they were members of the cloud to degree 1 or degree 0. So there were 2n candidate clouds, and the Problem of the Many is finding out how to preserve the intuition when faced with all these objects. It is unclear how increasing the range of possible relationships between each particle and the cloud from 2 to continuum-many should help here, for now it seems there are at least continuum-many cloud-like objects to choose between, one for each function from each of the n droplets to [0, 1], and we need a way of saying exactly one of them is a cloud. When van Inwagen addresses an objection like this one, he solves it by saying that not every function will correspond to an object. That is, he appeals to something like brute composition, although in this case it is mixed with fuzzy logic. But it is the bruteness not the fuzziness that does the philosophical work. So it does not look like this solution is any better than Markosian's brutal composition solution, and may even be worse given the contentious appeal to fuzzy logic.