Anticipated by Friedrich Nietzsche at the end of the 19th century, postmodernism emerged in full force in the latter part of the 20th century. Sire claims that, although thinkers argue constantly about how best to define it, postmodernism is essentially a worldview that questions all absolutes, narratives, and values—an expression of “incredulity toward metanarratives” (205). In part because it emerged within sociology rather than philosophy, postmodernism is more concerned with how we construct meaning than with what is objectively true. According to Sire, this fundamental shift in perspective is due to the gradual evolution of Western thought traced throughout the book, which can be seen as a three-stage evolution from premodern to modern to postmodern.

In premodern thought (represented by theism), the emphasis was on the metaphysical foundations of being. “Being is prior to knowing” (207), and being has its origin in God, the supreme being. Our ability to know God and all reality follows from this prime reality. From this knowledge of what is true follows ethics, or rules for how we live our lives. Finally, we can draw conclusions about the overall purpose of human life and the direction of history.