ABSTRACT
There are thus at least two kinds of complex causal relation: the chain kind and the constitution kind. If we wish to understand causation, we need to understand the basic causal relations, at least as found in the chain kind. That is, to understand what it is for A to cause B when the latter is a causal relation of the chain kind, requires understanding what it is for the intermediate, basic causal relations to hold. In the case of a complex causal relation of the constitution kind, it is may be that understanding what it is for A and B to be causally related does not require understanding what it is for the constituting causal relations to hold. For a complex causal relation of the constitution kind may be itself regarded as basic relative to its own level of explanation.
