  Conventionalist definitions account well for modern art, but have difficulty accounting for art’s universality – especially the fact that there can be art disconnected from “our” (Western) institutions and traditions, and our species.  They also struggle to account for the fact that the same aesthetic terms are routinely applied to artworks, natural objects, humans, and abstracta. Aesthetic definitions do better accounting for art’s traditional, universal features, but less well, at least according to their critics, with revolutionary modern art; their further defense requires an account of the aesthetic which can be extended in a principled way to conceptual and other radical art. (An aesthetic definition and a conventionalist one could simply be conjoined. But that would merely raise, without answering, the fundamental question of the unity or disunity of the class of artworks.) Which defect is the more serious one depends on which explananda are the more important. Arguments at this level are hard to come by, because positions are hard to motivate in ways that do not depend on prior conventionalist and functionalist sympathies. If list-like definitions are flawed because uninformative, then so are conventionalist definitions, whether institutional or historical. Of course, if the class of artworks, or of the arts, is a mere chaotic heap, lacking any genuine unity, then enumerative definitions cannot be faulted for being uninformative: they do all the explaining that it is possible to do, because they capture all the unity that there is to capture. In that case the worry articulated by one prominent aesthetician, who wrote earlier of the “bloated, unwieldy” concept of art which institutional definitions aim to capture, needs to be taken seriously, even if it turns out to be ungrounded: “It is not at all clear that these words – ‘What is art?’ – express anything like a single question, to which competing answers are given, or whether philosophers proposing answers are even engaged in the same debate….  The sheer variety of proposed definitions should give us pause. One cannot help wondering whether there is any sense in which they are attempts to … clarify the same cultural practices, or address the same issue” (Walton 2007). 