Decision-making typically requires judgments about causal relations: we need to know the causal effects of our actions and the causal relevance of various environmental factors. We investigate how several individuals' causal judgments can be aggregated into collective causal judgments. First, we consider the aggregation of causal judgments via the aggregation of probabilistic judgments, and identify the limitations of this approach. We then explore the possibility of aggregating causal judgments independently of probabilistic ones. Formally, we introduce the problem of causal-network aggregation. (...) Finally, we revisit the aggregation of probabilistic judgments when this is constrained by prior aggregation of qualitative causal judgments. (shrink)

I am grateful to Geoffrey Brennan, Campbell Brown, Franz Dietrich, Christian Elsholtz, Robert Goodin, Frank Jackson and David Soskice for very helpful comments and suggestions; and to the participants of a Social and Political Theory seminar at the ANU in February 2003 and the participants of a conference panel of the Australasian Association of Philosophy at the University of Adelaide in July 2003 for comments and discussion.