I analyze a well-known argument by Stuart Kauffman about complex systems and evolution to show it contains a hierarchy of non-mechanistic, non-causal explanations—which I would call, following Kauffman, “ensemble explanations”—quite closely resembling the explanations of the structural kind proposed in Huneman (2017), but lacking their absolute mathematical certainty, being based on results of non-exhaustive computer simulations. In Kauffman’s core argument ensemble explanations form an explanatory chain along a hierarchy of levels, where each explanans at one level gets itself recursively explained at the lower level. Explanations at adjacent levels turn out to be related not by mereological containment as in a multilevel mechanistic explanation, but by an analog to the relationship between two specifications at different levels of a specification/implementation hierarchy as understood by computer science. A mechanistic explanation grounds the whole hierarchy enabling the explanatory chain. Interestingly, the preliminary production of ensemble explanations enables the multilevel mechanistic explanations of systems manifesting what Bedau (1997) defines as weak emergence.