In 1786, as Kant's philosophy became prominent in Germany, it remained marginal to the hottest philosophical issue of the day: the relationship between faith and reason. The preceding year had seen two posthumous biographies of Gotthold Lessing, the dominant intellectual presence in Germany for a generation. In one, F. H. Jacobi claimed that in Lessing's dying days, he confessed to being a “pantheist”, which was essentially synonymous with atheism. In another, Moses Mendelssohn defended Lessing against such charges. The apparently biographical disagreement became a hotly contested philosophical dispute about the Enlightenment: could one be an “enlightened”, rational philosopher without giving up religion and morality? Into this debate came a series of “Letters on the Kantian Philosophy” by an early disciple of Kant's philosophy. Karl Reinhold argued that the apparently arcane and incomprehensible Critique of Pure Reason actually “secures … a better future for our descendents” by providing “universally satisfying” answers to “the most pressing philosophical needs of our time” (Reinhold 2006: 16).

Today's philosophical scene is quite different. It is no longer assumed that atheism is immoral or dangerous. If anything, most professional philosophers hold the opposite view, that “God is not great” and religion is a dangerous “God delusion” (see Dawkins 2006; Hitchens 2007). But we continue to deal with problems Reinhold hoped Kant had solved forever. Despite atheism's popularity among philosophers, many people still find mere reason insufficient for making sense of human life.