Durkheim's idea of moral force is the key to his epistemological argument. Without it the argument necessarily falls back on either the problem of general ideas based on sensation, or, if one abandons empiricism and pragmatism, on idealism. Durkheim's argument is intended to establish a third alternative. That Durkheim has been interpreted as having adopted both empiricism and apriorism is a clear indication that his idea of moral force has not been understood.

The order in which Durkheim presents his argument is at least partly to blame for this misunderstanding. For one thing, the discussion of moral force only really begins in Chapters Six and Seven of Book II, of The Elementary Forms. But, even then, the argument is not at all satisfactory until the connection between rites and emotions is made definitively in the discussion of causality, which does not occur until Book III (see my Chapter Eight). That later discussion is the only one in The Elementary Forms to clearly and unambiguously locate rites as the cause of a category of the understanding. This earlier discussion of moral force still combines considerations of beliefs with rites, which ultimately obscures Durkheim's argument that beliefs and ideas are caused by rites, although he does make the argument repeatedly here, in conjunction with his discussion of beliefs.

It is curious that Durkheim allowed the discussion of moral force to remain ambiguous and that it appears so late in the text.