John Stuart Mill argues that morality is binding because under favorable circumstances, human beings can have motives to act as it requires. Immanuel Kant argues that the Categorical Imperative is binding on any rational agent. He does not argue that this is so only under certain favorable circumstances. Morality for Kant is not contingent as it is for Mill. The Categorical Imperative is rather binding on any rational agent. Kant makes a strong argument that suggests a number of important conclusions for moral thought.
John Stuart Mill begins his discussion of moral theory with a definition of utilitarianism, stating that this is the creed that accepts utility as the foundation of morals, meaning the greatest happiness principle. This holds that actions are right in proportion as they tend to promote happiness, and wrong as they tend to produce the reverse of happiness. Happiness means the intended pleasure and the absence of pain, while unhappiness means pain and the privation of pleasure.
For Mill, the acts we choose are themselves happiness for us. It is not that they are merely the means to an end but that they are also an end in themselves. Happiness for Mill is a unified way of life rather than an abstraction toward which we tend as we make our choices and behave as our analyses dictate. "Living right" is a moral proposition that is more than an abstraction based on concepts of pleasure and pain and the development of a sum total of happiness. For Mill,