There is a way of thinking about philosophy, and about social science, such that it doesn't actually matter, for the purposes of doing social science, how philosophical questions are answered. In one sense, of course, it doesn't. If one is a realist, at least -and one ought to be -then one will think that the fact that one believes p, for example, implies nothing very much about the world other than that one does hold that belief. The world is as it is, one will say, regardless of which philosophical positions are correct. Even concept-dependent features of the world do not simply pop into existence via solipsistic command. But the "irrelevancy thesis," as I'll call it, is not an elliptical expression of realism. The idea that empirical inquiry is or should be unencumbered by the preoccupations of philosophers is a meta-theoretical principle, not a first-order ontological claim. I'm interested in the irrelevancy thesis as applied to the question of what causation is. Social scientists needn't care about such a question, say proponents of the thesis. If nothing else, competing answers can be true simultaneously. And besides, one can certainly put forward a causal explanation without holding any beliefs about what causation is. Lest I be accused of setting up straw men, let me say that these are positions that were defended with great conviction at a recent academic conference on the future of American sociology.It is not very hard to show that the irrelevancy thesis is false. Manifestly, there are real differences between alternate accounts of causation (though the important ones are not between alternate iterations of Humeanism), and those theories that do genuinely differ from one another are patently irreconcilable. Moreover, insofar as a causal explanation is a causal explanation, it trades on a concept of causation, if only implicitly. And the approach that one takes to causation, even if one does so unreflectively, fixes what one may believe causes to be like, and by extension what sort of entity one will be in a position to think can even be a cause, as well as fixing what one will think is or is not happening when causation occurs. For these reasons alone, apart from various others, it is simply not true that one can offer up a causal explanation without thereby having committed oneself to a view about what causation is, i.e., without implicitly having weighed in on a fundamental question of metaphysics. At this level, in fact, there is not much more to be said. One either abides by certain principles of discursive reasoning or one does not. But the irrelevancy thesis does not just lead its proponents to say foolish things at conferences that they may not really mean. Disregard for philosophy has also led to muddled thinking about so-called "causal mechanisms." And here, at least, there is something to be sorted out.Towards that end, the discussion below is organized as follows: first, I establish a twopart typology that allows for a distinction to be made between passivist theories of causation and produ...