It should be clear by now that Durkheim's sociology of knowledge was developed in reaction to and borrowed heavily from the eclectic spiritualist tradition in philosophy. One of the elements Durkheim adopted from this tradition can be seen in the argument by which he introduced his sociological theory of the categories in The Elementary Forms of Religious Life (1912a). As we have seen, French thinkers beginning with Cousin presented their theories of the categories by offering first an eliminative argument criticizing all previous empiricist and a priorist accounts of them. They maintained that the empiricists could not account for the universality and necessity of the categories and that their Kantian rationalist opponents could not explain or justify the way in which the categories are imposed on our experience of the external world. Durkheim added to this eliminative argument that the Kantians could not account for the cultural variability of the categories, either. But in making this change, he thus appeared to have imposed rather conflicting demands on a theory of the categories, requiring that it explain both their universality and their variability. In order to remove this conflict, I have distinguished the categories from their collective or cultural representations and argued that it is only the cultural representations of the categories that are variable. That is, each culture has the same set of categories, including space, time, and causality, but has developed different systems of representations for thinking and communicating about them.