Direct and indirect causes

Everybody agrees that the distinction between direct and indirect causation is important. And it seems easy to draw, if an analysis of causation in general is available. The causal influence of one event on another is direct, if it is not mediated by other events in between; otherwise it is indirect. The trouble is with the proviso. Indeed, I contend that the order of analysis must be reversed because the distinction is required for a successful analysis of causation. Such an analysis perhaps proceeds best in two steps: the first analyses direct causation, and the second extends the analysis to indirect causation and thus to causation in general. Such a strategy is at least plausible. For direct causation is a very special case and so may be supposed to be more easily explicable. Then, one might say that the relation "A is a cause of B"