AbstractTranscendental idealism is the basic worldview shaping Kant's critical philosophy, but its proper interpretation is enormously contested. I identify five constraints on an adequate interpretation, which collectively stand in apparent tension. These serve to highlight internal difficulties of the view itself, and also to reveal serious challenges for both the more standard phenomenalist and deflationary interpretations, and newer “moderate metaphysical” approaches. Difficulty centers on how to reconcile Kant's widespread claims that things in themselves are identical to appearances, in some sense, with his equally widespread insistence that they are (and must be) non‐identical. I suggest that Kant's view must have been that the objects of knowledge are (strictly) partially mind‐dependent, and that the Kantian hylomorphic idea of formal idealism can explain this partial mind‐dependence. The result points toward an anti‐metaphysical interpretation of Kantian idealism, according to which the metaphysical question of identity between things in themselves and appearances should be rejected as illegitimate, rather than answered.