Ethical rationalism

Moral rationalism, also called ethical rationalism, is a view in meta-ethics (specifically the epistemology of ethics) according to which moral principles are knowable a priori, by reason alone. Some prominent figures in the history of philosophy who have defended moral rationalism are Plato and Immanuel Kant. Perhaps the most prominent figure in the history of philosophy who has rejected moral rationalism is David Hume. Recent philosophers who have defended moral rationalism include Richard Hare, Christine Korsgaard, Alan Gewirth, and Michael Smith.

Moral rationalism is similar to the rationalist version of ethical intuitionism; however, they are distinct views. Moral rationalism is neutral on whether basic moral beliefs are known via inference or not. A moral rationalist who believes that some moral beliefs are justified non-inferentially is a rationalist ethical intuitionist. So, rationalist ethical intuitionism implies moral rationalism, but the reverse does not hold.

There are two main forms of moral rationalism, associated with two major forms of reasoning. If moral reasoning is based on theoretical reason, and is hence analogous to discovering empirical or scientific truths about the world, a purely emotionless being could arrive at the truths of reason. Such a being wouldn't necessarily be motivated to act morally. Beings who are motivated to act morally can also arrive at moral truths, but needn't rely upon their emotions to do so.

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