  The cluster version of the family resemblance view has been defended by a number of philosophers (Bond 1975, Dissanayake 1990, Dutton 2006, Gaut 2000). The view typically provides a list of properties, no one of which is a necessary condition for being a work of art, but which are jointly sufficient for being a work of art, and which is such that at least one proper subset thereof is sufficient for being a work of art. Lists offered vary, but overlap considerably. Here is one, due to Gaut: (1) possessing positive aesthetic properties; (2) being expressive of emotion; (3) being intellectually challenging; (4) being formally complex and coherent; (5) having the capacity to convey complex meanings; (6) exhibiting an individual point of view; (7) being original; (8) being an artifact or performance which is the product of a high degree of skill; (9) belonging to an established artistic form; (10) being the product of an intention to make a work of art (Gaut 2000). The cluster account has been criticized on several grounds. First, given its logical structure, it is in fact equivalent to a long, complicated, but finite, disjunction, which makes it difficult to see why it isn’t a definition (Davies 2006). Second, if the list of properties is incomplete, as some cluster theorists hold, then some justification or principle would be needed for extending it.  Third, the inclusion of the ninth property on the list, belonging to an established art form, seems to regenerate (or duck), rather than answer, the definitional question. Finally, it is worth noting that, although cluster theorists stress what they take to be the motley heterogeneity of the class of artworks, they tend with surprising regularity to tacitly give the aesthetic a special, perhaps unifying, status among the properties they put forward as merely disjunctive.  One cluster theorist, for example, gives a list very similar to the one discussed above (it includes representational properties, expressiveness, creativity, exhibiting a high degree of skill, belonging to an established artform), but omits aesthetic properties on the grounds that it is the combination of the other items on the list which, combined in the experience of the work of art, are precisely the aesthetic qualities of the work (Dutton 2006). Gaut, whose list is cited above, includes aesthetic properties as a separate item on the list, but construes them very narrowly; the difference between these ways of formulating the cluster view appears to be mainly nominal. And an earlier cluster theorist defines artworks as all and only those things that belong to any instantiation of an artform, offers a list of seven properties all of which together are intended to capture the core of what it is to be an artform, though none is either necessary or sufficient, and then claims that having aesthetic value (of the same sort as mountains, sunsets, mathematical theorems) is “what art is for” (Bond 1975). 