Robustly realistic metaphysical readings of Kant’s mature views have become popular in recent years, largely because of the apparent coherence of applying unschematized categories like that of causation to things in themselves. There is, however, an overlooked problem that arises even for robust realist readings that privilege unschematized categories. The problem is that Kant provides all the elements for what is now called a ‘debunking explanation’ of metaphysical representations of things in themselves. His account of the categories as arising from (...) mere forms of judgment, and being applied primarily for the unity of consciousness, is detached from the issue of whether there are causes among things in themselves. This detachment seems to imply that it would be a huge coincidence if unschematized categories corresponded to any such causes. After making this argument, using the category of causation as my central case, I consider three potential responses: that Kant’s account implicitly appeals to things in themselves’ causation, that Kant has a separate account of non-coincidental representation, and that Kant’s account is merely incomplete in a way that poses no debunking threat. None of these responses, I argue, are successful, so I conclude that either robustly realistic metaphysical readings are mistaken, or there is internal incoherence in Kant’s views. (shrink)