Kant's theory of ethics is based upon a concept of hypothetical reciprocity known as the categorical imperative. The categorical imperative states that in order to know what the moral course of action in any given situation is, one should assume that each individual in society would behave likewise. Then, one should ask the question: "would I want this behavior committed toward me?" In other words, would I want to be the recipient of the action I am considering? If the answer is yes, then the action is moral.
A utilitarian framework of ethics allows people to use others as means to a greater end. This could result in a society where harming others is considered acceptable as long is the anticipated end is justifiable enough. Virtue ethics assumes that only certain people are capable of behaving morally, and that the practice of virtue is one that might be limited to the upper classes; those with the leisure, education, and social standing necessary to achieve Aristotle's virtues.