Final answer:
Immanuel Kant's understanding of moral law is based on his concept of the categorical imperative, which dictates that actions are only moral if they can be made into universal laws applicable to everyone. This includes perfect and imperfect duties and is guided by human reason and rationality.
Step-by-step explanation:
Kant's Moral Law and the Categorical Imperative
Immanuel Kant's understanding of the moral law is centered around the concept of the categorical imperative, which is used to test the morality of a proposed action. According to Kant, an action is moral if it can be universalized, meaning it can be consistently applied to everyone without contradiction. This idea is encapsulated in his famous principle: "Act only according to that maxim whereby you can, at the same time, will that it should become a universal law." Furthermore, Kant distinguished between perfect duties, such as not lying or stealing, which we are obliged to follow always, and imperfect duties, which allow for some discretion in their application. Rational beings use their capacity for reason to identify these moral laws that guide ethical behavior. In this way, human reason elevates us, prompting actions that are duty-bound and not merely serving of subjective desires.
Kant's contribution to ethicaiprogress includes his belief that reason can lead individuals to identify ethical principles that should apply universally - these are the categorical imperatives that can improve society.