The Ideal of a Rational Morality collects the most important essays by the distinguished moral philosopher Marcus G. Singer. Its guiding theme is the concept of a morality based in reason, which is presupposed in ordinary moral contexts and provides an ideal for improving ordinary morality and correcting moral judgements. Singer makes compelling claims that certain fundamental presuppositions are inescapable in moral thought, that fundamental moral principles can be proved, and that the concepts of truth and 'common sense' are essential to ethics.