By Onora O'Neill
From Matters of Life and Death, ed. Tom Regan
Copyright 1986, McGraw-Hill Publishing Company.
Excerpted in Contemporary Moral Problems, ed. James E. White
Copyright 1994, West Publishing Company
Kant's moral theory has acquired the reputation of being forbiddingly difficult to understand and, once understood, excessively demanding in its requirements. I don't believe that this reputation has been wholly earned, and I am going to try to undermine it.... I shall try to reduce some of the difficulties.... Finally, I shall compare Kantian and utilitarian approaches and assess their strengths and weaknesses.
The main method by which I propose to avoid some of the difficulties of Kant's moral theory is by explaining only one part of the theory. This does not seem to me to be an irresponsible approach in this case. One of the things that makes Kant's moral theory hard to understand is that he gives a number of different versions of the principle that he calls the Supreme Principle of Morality, and these different versions don't look at all like one another. They also don't look at all like the utilitarians' Greatest Happiness Principle. But the Kantian principle is supposed to play a similar role in arguments about what to do.
To learn the short version of Kant, read on here.