Although this theory sounds good on paper, it crumbles when one attempts to put it into practice because it clashes with the average person’s moral intuition. For example, Kant would say that lying is always wrong, but what if you had to lie to save someone’s life? Most people would say that in this situation, lying is permissible, but a Kantian would disagree.
Needless to say, such discrepancies between Kantian beliefs and a typical person’s “gut instinct” abound. These disagreements are enough to discount the unyielding nature of deontology. Our world is not as black-and-white as Kant would like to suggest, and ignoring its many gray areas will only cause harm.