关键词: 道德律, 伦理学, 康德

Abstract: Kant believed that moral law was an outcome of self-lawmaking of reason,and was valid for all the rational being. But he was harassed by how to make an argument for the validity of moral law despite his great efforts. Kantian argument went through four phases: transcendent deduction, factual corroboration, reduction to absurdity in practice and rational revelation. Ultimately Kant related the validity of moral law with God's existence, and tried to prove the former depend on the latter. This indicates that Kantian assurance of moral law conceal theological precondition.

Key words: moral law, ethics, Kant