I argue that Kant’s transcendental idealism and Strawson’s descriptive metaphysics are both examples of what I call methodological conservativism. Methodological conservativism involves the claim that a subset of common first-order beliefs is immune to revision. I argue that there are striking differences between their respective commitments to this position, however. For Kant, his conservativism is based upon a commitment to the reliability of particular results of the sciences of his day. For Strawson, in contrast, his conservativism is based upon his (...) attempted liberation of arguments for the necessity of a certain conceptual scheme from any particular scientific commitments. In fact, for Strawson, no change in scientific commitments could displace the conceptual scheme employed to navigate the manifest world of ordinary perceptual experience. Each approach brings with it challenges with regard to how to accommodate potential scientific theory change. (shrink)