Kant argues that morality can’t be based on merely the interests, wants, desires, and preferences people have at any given time. These factors are contingent, so they could hardly serve as the basic for universal moral principles, such as universal human rights.
The utilitarian’s happy principle “contributes nothing whatever toward establishing morality, since making a man happy is quite different from making him good and making him prudent or astute in seeking his advantage quite different from making him virtuous.”
The consequences of our acts are not always in our control and things do not always turn out as we want. We generally ought not to be blamed or praised for what is not in our control. However, Kant believed that our motives are in our control. We are responsible for our motive to do good and bad, and thus it is for this that we are held morally accountable