t "the moral law is valid for us not because it interests us, but rather, the moral law interests us because it is valid for us as men, since it has sprung from our will as intelligence and hence from our proper self" (Immanuel Kant 'Grounding for the Metaphysics of Morals'). He says that there is no possibility in knowing why we are interested in universal maxims and therefore morality, as the rational part of us exists outside time and space and we can therefore not achieve any understanding of it is this world.I do not see this as a satisfactory answer in any way. Having based his entire view of morality on the idea of the categorical imperative, Kant is unable to substantiate his claim that we are capable of acting on reason alone. He merely dodges the issue by saying that there is no possibility of understanding how a categorical imperative can motivate.However, this does not invalidate the rest of Kant's argument in the least. It is still possible to argue that morality can only occur through the categorical imperative while holding the Humean idea that reason alone can never motivate, and so conclude that morality doesn't exist in reality.In conclusion, we can see that both the two theories have a number of things in common as well as some important differences. Both made a significant break with past moral theorists in putting forward a morality that does not according to Kant "needthe idea of another being above man, for a man to recognize his duty" (quoted in 'The Concise Encyclopedia of Western Philosophy and Philosophers' Ed. J.O. Urmson). Whereas past moral theories had seen duties as laid down by God, Hume and Kant saw morality as rooted in humans themselves.However from here the theories diverge. Hume sees moral judgements as being caused by sentiments of pain or pleasure within an agent as reason alone can never motivate, whereas Kant see the only moral actions as being those caused by reason alone, or the categor...
