 The Humean regularity theory, where causation is instantiation of regularity, presupposes that events can be sorted into types. A type is a class of resembling events. Based on the best systems account, we may now appeal to laws of nature in order to determine which events are similar and which are dissimilar. Suppose it is a law that all events \(a\) of type \(A\) are followed by events \(b\) of type \(B\). Then the events or objects similar to \(a\) are just the other instantiations of type \(A\), and likewise for type \(B\). But the law-making feature depends on epistemic considerations, and so the types determined by those laws depend on epistemic considerations. Hence, falling back to a Humean regularity theory does not solve the issue. We still need a way to sort events into types. But which events resemble each other comes in degrees and depends on the respects of comparison. The degrees of similarity and respects of comparison are not fixed by the world understood as the collection of all particular spatiotemporal matters of fact. The degrees and respects are rather epistemic components which depend on the categories and classification schemes we use. A related problem are gerrymandered categories or properties like “grue”, as studied by Goodman (1955) in his new riddle of induction.