HUME TO HEGEL In his sixties, Kant turned his attention to ethics and aesthetics in three seminal works: Fundamental Principles of the Metaphysics of Morals (1785); The Critique of Practical Reason (1788); and The Critique of Judgement (1790) In the Wrst two of these he aimed to set out critically the synthetic a priori principles of practical reason just as he had, in his Wrst Critique, set out the synthetic a priori principles of theoretical reason The starting point of Kant’s moral theory is that the only thing that is good without qualiWcation is a good will Talents, character, and fortune can be used to bad ends and even happiness can be corrupting It is not what a good will achieves that matters; good will, even if frustrated in its eVorts, is good in itself alone What makes a will good is that it is motivated by duty: to act from duty is to exhibit good will in the face of diYculty Some people may enjoy doing good, or proWt from doing good, but worth of character is shown only when someone does good not from inclination, but for duty’s sake To act from duty is to act out of reverence for the moral law, to act in obedience to a moral imperative There are two sorts of imperative, hypothetical and categorical A hypothetical imperative says: if you wish to achieve a certain end, act in such-and-such a way The categorical imperative says: no matter what end you wish to achieve, act in such-and-such a way There are as many sets of hypothetical imperatives as there are diVerent ends that human beings may set themselves, but there is only one categorical imperative which is this: ‘Act only according to a maxim by which you can at the same time will that it shall become a universal law.’ Whenever you are inclined to act in a certain way—for instance, to borrow money without any intention of paying it back—you must always ask yourself what it would be like if everyone acted in that way Kant oVers another formulation of the categorical imperative: ‘Act in such a way that you always treat humanity, whether in your own person or in the person of any other, never simply as a means, but always at the same time as an end.’ As a human being, Kant says, I am not only an end in myself, I am a member of a kingdom of ends, a union of rational beings under common laws In the kingdom of ends, we are all both legislators and subjects A rational being ‘is subject only to laws which are made by himself and yet are universal’.9 Kants’s moral philosophy is discussed at length in Ch 107