Priority monism has been criticised on the grounds that monists cannot give an informative story about how the world is heterogeneous: how can there be qualitative variation in the world, given we cannot explain the world’s qualitative variation in terms of its proper parts? I will argue that none of the traditional solutions to this problem are plausible, and instead argue that we should hold that what accounts for the world’s heterogeneity is that the Cosmos is identical to the collective (...) plurality of all the world’s tropes, and each individual trope, in the plurality, is non-distributively grounded in the plurality/bundle of all the world’s tropes. I go onto note that as well as providing a solution to the monistic problem of heterogeneity, this view – which I call (PUT) – could well be a promising trope bundle theory in its own right. (shrink)