Kant claimed that moral language was unique because moral statements were both synthetic and a priori. This means that a statement is knowable without before experiencing from pure reason, but needs experience for verification.
Kant felt that he had to act in a certain way. He was aware of the is/ought, the difference between something being a matter of fact, and something that is regarded as an obligation. He therefore concluded that what is good and what is bad should begin with good will. In his book, Groundwork for the Metaphysics of Morals (1785), he argues the highest form of good is goodwill. To have a good will is to do ones duty. To do ones duty is to do the right thing, obligatory and not to perform what is forbidden.
The categorical imperative helps us to determine which actions are obligatory and which are forbidden. It tells us what we ought to do, “All in imperatives command either hypothetically or categorically… If the action would be good simply as a means to something else, then the imperative is hypothetical; but if the action is represented as a good in itself… then the imperative is categorical.”
Kant argued morality is prescriptive, moral statements are categorical in that they prescribe actions irrespectively of the result.
There are three principles of the categorical imperative,
Universal law
Humans as ends not merely as means
A kingdom of ends
Universal law, “act only according to that maxim (principle or rule) by which you can at the same time will that it should become universal law”, a person’s actions would become a law applicable to everyone.
“Act that you treat humanity, both in your own person and in the person of every other human being, never merely as a means, but always at the time as an end.” This means that humans play an important part in any moral equation.
“Act as if you were through your maxim a law-making member of a kingdom of ends”, Kant believed humans should behave as though every other individual was an ‘end’. humans are capable of autonomous moral choice-making.