I argue that high level causal relationships are often more fundamental than low level causal relationships. My argument is based on some general principles governing when one causal relationship will metaphysically ground another—a phenomenon I term derivative causation. These principles are in turn based partly on our intuitive judgments concerning derivative causation in a series of representative examples, and partly on some powerful theoretical considerations in their favour. I show how these principles entail that low level causation can derive from (...) high level causation, and in particular that neural causation can derive from mental causation. I then draw out several important consequences of this result. Most immediate among these are the implications the result has for aspirations to reduce high level causation to its low level counterpart. But the result also bears on the possibility of downward causation, the relationship between counterfactuals and causation, and the idea—familiar from both the literature on the exclusion problem and the literature on proportionality constraints on causation—that causal relationships at different levels compete for their existence. (shrink)