There are two main meanings in Kant’s concept of moral certainty (moralische Gewissheit, certitudo moralis): first, it applies to the kind of certainty embodied in rational faith in the existence of God and a future life; second, it applies to the conscientiousness (Gewissenhaftigkeit) required of an agent in the practice of moral judgement. Despite the growing attention to Kant’s theory of conscience and his concept of conscientiousness, this article is the first to discuss ‘moral certainty’ as the aim of ‘conscientiousness’ (...) and to highlight the relevance of both notions in regard to moral education and the purposes of Kant’s ethical doctrines of method. (shrink)