Transcendental Idealism: Kant's philosophical view that the structure of human experience is shaped by the mind's own a priori concepts and categories, rather than being a direct representation of an independent external reality.
Categorical Imperative:Kant's moral principle that an action is only morally permissible if it could become a universal law of nature, and that one should treat others as ends in themselves, never merely as means.
Noumenon: In Kant's philosophy, the noumenon is the thing-in-itself, the underlying reality that exists independently of human perception and understanding, as opposed to the phenomenal world that we can experience and know.