Perfect ethical duties have usually puzzled commentators on Kant's ethics because they do not fit neatly within his taxonomy of duties. Ethical duties require the adoption of maxims of ends: the happiness of others and one's own perfection are Kant's two main categories. These duties, he claims, are of wide obligation because they do not specify what in particular one ought to do, when, and how much. They leave ‘a latitude for free choice’ as he puts it. Perfect duties, however, (...) such as the duties of respect, to avoid suicide, lying, and servility, do not appear to require the adoption of ends but only the performance or omission of specific types of actions. The puzzle is how these duties can be ethical, and therefore wide. Faced with this difficulty, Mary Gregor denies that perfect ethical duties are wide. She claims that they are an ‘anomaly’ and that they do not belong to ethics proper but to moral philosophy in general. She argues that these duties are derived from the categorical imperative, instead of, as Kant himself appears to have thought, the first principle of virtue. Taking a very different approach, Onora O'Neill finds the perfect/imperfect distinction of little importance and suggests doing without it altogether. Most other interpreters also assume that ‘wide’ is opposed to ‘perfect’ so that a wide perfect duty is a conceptual impossibility. (shrink)

El principio de tolerancia recibe un giro novedoso en la obra de John Rawls con su propuesta de aplicarlo a la filosofía misma.