Over the course of the Commentary sections on the specific chapters, we have reviewed a number of criticisms of Kant. Some philosophers have argued that in practice our moral beliefs are based on intuitions, not on reason. Hegel pointed out that moral beliefs can never be unconditional because moral questions must be resolved in the context of the society in which we live. ##Nietzsche## argued that reason is not the source of moral freedom, but is rather an impediment to free choice.
The common thread of all these criticisms is that Kant's position is too abstract to be useful. As human beings, we live in a particular place at a particular time. It is not necessarily possible or desirable for us to separate our rationality from the other features of our personality. We may reason about issues in abstract terms, and we may imagine the situations of other people, yet our starting point must always be our own life situation.
It is a typical feature--a common "mistake," if you will--of Enlightenment thinking to presume that we can ignore our own particularities and discover universal principles of reason. This "mistake" may have been possible because Enlightenment philosophers came from a relatively homogeneous culture (that of eighteenth-century Europe) and from a relatively homogeneous class position (one of relative financial security). This homogeneity may have led Enlightenment thinkers to oversimplify certain questions, presuming that their answers were "rational" when they in fact depended on cultural assumptions.
On the other hand, Kant's philosophy--and Enlightenment philosophy in general-- is by no means a philosophy of privilege. Indeed, Kant's ideas are radically egalitarian. According to Kant, moral truths are not received from on high through divine revelation or inspiration. Rather, they are based on reasons that make sense to all people (indeed, all rational beings) who bother to think about them. The passion with which people espouse moral views suggests that many people continue to share Kant's view that moral principles must be absolute and universal. Late twentieth-century people may be more aware of diversity than Kant was. As a result, we may have less confidence than him that what makes sense to us will make sense to other people. Nevertheless, in our day as in Kant's, people do tend to think that there is more to their moral beliefs than mere cultural prejudice.
Like all great philosophers, Kant's arguments have provoked a wide range of responses, positive and negative. Whatever we make of Kant's views, it would be difficult to underestimate the historical impact of his "Copernican Revolution" in philosophy. Even today, nearly two hundred years after his death, Kant's arguments remain a powerful presence in philosophy.
The last note on Darwin and evolution displays a common misconception about evolution, that is, the anthropomorphism of a process. Organs do not develop to help with survival, the organs that are best suited for survival survive. There is no purpose in an organ's origins.