||In many ways, Michael Smith's The Moral Problem is the both the most important work on moral judgment and the best place for someone interested in the topic to begin thinking seriously. Smith, better than anyone else, sets out the problems which have dominated the philosophical agenda on moral judgment for the last two decades and presents a novel and powerful cognitivist, Humean, internalist solution to these problems. R.M. Hare's The Language of Morals offers the classic non-cogntivist statement of internalism, while David O. Brink's Moral Realism and the Foundations of Ethics provides a persuasive case for cognitivist externalism and Jonathan Dancy's Moral Reasons argues for cognitivist non-Humeanism. Dancy's work draws in important ways from Thomas Nagel's The Possibility of Altruism, and Russ Shafer-Landau's Moral Realism: A Defense is a worthwhile follow up on both works. Those who wish to approach the problem from a more historical direction may wish to begin with Book III of David Hume's Treatise of Human Nature, Immanuel Kant's Critique of Practical Reason, and Chapter III of John Stuart Mill's Utilitarianism. A more recent work which finds deep inspiration from Kant's work on moral motivation is Christine Korsgaard, The Sources of Normativity.