 Perhaps with chaos explanation we should either search for a process yielding the “stretching and folding” in the dynamics (causal form of explanation) or we should search for the common properties such behavior exhibits (unification form of explanation) underlying the behavior of the nonlinear systems of interest. In other words, we want to be able to understand why systems exhibit SDIC, aperiodicity, randomness, and so forth. But these are the properties characterizing chaotic behavior, so the unification account of explanation sounds like it may ultimately involve appealing to the properties in need of explanation. 