Schleiermacher rejected both Deism, which reduced Christianity to morals, and Protestant orthodoxy, which upheld an elaborate system of doctrines. In his 1799 book, On Religion: Speeches to Its Cultured Despisers, he tried to show that religion is based on feeling, not on knowledge or morality. His goal was to gain a hearing for religion among people who had previously rejected it. Scheiermacher argued that the essence of religion is the feeling of absolute dependence on God. This feeling can only be experienced through a profound self-consciousness. Schleiermacher is remembered as "the father of liberalism" because he maintained the essence of religion is not revelation outside of the self but feeling inside of the self. Such religious expression will naturally change with time and circumstance. Later the historian Adolf von Harnack argued that doctrine develops within particular historical contexts; but Karl Barth rejected Schleiermacher's view that religion is based on feeling.