The overarching agenda of Kant’s philosophy was to reconcile the claims of morality and religion with scientific knowledge, giving human nature a place within physical nature. Our knowledge depends on sensory states plus the mind’s activity. According to his transcendental idealism, how we perceive and conceive depends on the latter.
There is a vital practical dimension to Kant’s conception of reason. We are not merely perceiving beings; we are agents. We experience of moral obligation, the tension between our individual desires and the requirements of morality. Kant was a solid believer in human freedom and moral responsibility. He saw us as rational beings who can make choices that are not predetermined; especially when we act on moral reasons.
His late work Religion within the Bounds of Bare Reason wrestles with profound problems of human nature, and suggests new versions of old theological insights. He talks of the “radical evil” in human nature, acknowledging our “frailty” and our “impurity”. He insists that the evil in us is a result of our own choice, but evil is an unavoidable feature of our condition as needy but rational beings:
The later sections of all three Critiques touch on theological themes. Kant’s understanding of religion is serious, even if it departs from Christian orthodoxy.
Kant was the deepest Enlightenment thinker, but he had a realistic sense of the dark side of human nature, which has been amply confirmed since. His philosophy leaves us with a combination of hope for gradual social progress, and for divine grace in the transformation of our fallen human nature.