Rational intuitionism (not to be confused with “intuitionism”) is a meta-ethical view that, starting with his Dewey Lectures in 1980, Rawls consistently contrasts with constructivism. Rawls notes that there have been variations on the doctrine, “but in one form or another it dominated moral philosophy from Plato and Aristotle onward until it was challenged by Hobbes and Hume, and, I believe, in a very different way by Kant.” He further associates it with “in the English tradition by Clarke and Price, Sidgwick and Moore, and [it was] formulated in its minimum essentials by W. D. Ross. With qualifications, it was accepted by Leibniz and Wolff in the guise of perfectionism, and Kant knows of it in this form” (CP 343). Obviously, the idea of rational intuitionism is compatible with many different theories of the content of morality.

In Political Liberalism, Rawls identifies four features characteristic of rational intuitionism. First, and most importantly, it holds that “moral first principles and judgments, when correct, are true statements about an independent order of moral values; moreover, this order does not depend on, nor is it to be explained by, the activity of any actual (human) minds, including the activity of reason” (PL 91). Second, our knowledge of these principles and judgments is the result of exercising our theoretical (as opposed to practical) reason. Third, rational intuitionism is able to rely on a “sparse conception of the person” (PL 92). Although forms of it may rely on a richer conception of the person, all that is required is to understand the self as a knower that is capable of being motivated to act on the moral principles that it recognizes for their own sake. Finally, “rational intuitionism conceives of truth in a traditional way by viewing moral judgments as true when they are both about and accurate to the independent order of moral values. Otherwise they are false” (PL 92).