In 1953 Herbert Simon provided an explication of the causal relation which was to become quite popular among economists. The “causal ordering” was established in a complete system of equations, whose nature has not been completely clarified, neither in the 1953 nor in subsequent papers by Simon and other co-authors. This paper purports to show that serious problems are likely to arise when equilibrium conditions are explicitly included (as it should be) among the equations composing the model. This is especially true when the causal ordering is used for assigning modal indeces to factual propositions, as in the analysis of counterfactuals proposed by Simon-Rescher. So, despite its similarity with the explication of causality advanced by other authors (Wold being the explicit reference), it is not sure that Simon fully succeeded in explicating the “intuitive” notion of causality.