Schaeffer's book "A Christian Manifesto" was published in 1981 and later delivered as a sermon in 1982. It was intended as a Christian answer to "The Communist Manifesto" of 1848 and the "Humanist Manifesto" documents of 1933 and 1973. Schaeffer's diagnosis is that the decline of Western Civilization is due to society having become increasingly pluralistic, resulting in a shift "away from a world view that was at least vaguely Christian in people's memory… toward something completely different." Schaeffer argues that there is a philosophical struggle between the people of God and the secular humanists. In the sermon version of the book, Schaeffer defines secular humanism as the worldview where "man is the measure of all things". He claims that critics of the Christian right miss the mark by confusing the "humanist religion" with humanitarianism, the humanities, or love of humans. He describes the conflict with secular humanism as a battle in which "these two religions, Christianity and humanism, stand over against each other as totalities." He writes that the decline of commitment to objective truth that he perceives in the various institutions of society is "not because of a conspiracy, but because the church has forsaken its duty to be the salt of the culture."