  As was noted above, a major problem for Vaihinger’s early view, as for many of the Neo-Kantians of his day, was the status of the thing in itself. Vaihinger now consistently rejects this notion, predictably labelling it a fiction. Given that things in themselves are supposed to be transcendent substances that causally affect us, this rejection follows immediately from his view that the concepts of substance and cause are themselves fictions (PAO 55–56). True to form, however, Vaihinger still holds that the concept of things in themselves has some utility: as Cohen had argued, it serves as a “limiting concept” (PAO 55), ensuring that we restrict our inquiries to what is empirically given to us. As we have seen, Vaihinger puts an instrumentalist spin on this Kantian idea; all knowledge is empirical in the sense that our guiding cognitive aim is the prediction and control of empirical phenomena, not correspondence to objective reality (though, once again, it bears emphasizing that Vaihinger does not seem to be claiming that such correspondence is impossible, only that it is incidental to our main epistemic aim).