First, a definition. This from PBS of all places:
"A general and wide-ranging term which is applied to literature, art, philosophy, architecture, fiction, and cultural and literary criticism, among others. Postmodernism is largely a reaction to the assumed certainty of scientific, or objective, efforts to explain reality. In essence, it stems from a recognition that reality is not simply mirrored in human understanding of it, but rather, is constructed as the mind tries to understand its own particular and personal reality. For this reason, postmodernism is highly skeptical of explanations which claim to be valid for all groups, cultures, traditions, or races, and instead focuses on the relative truths of each person. In the postmodern understanding, interpretation is everything; reality only comes into being through our interpretations of what the world means to us individually. Postmodernism relies on concrete experience over abstract principles, knowing always that the outcome of one's own experience will necessarily be fallible and relative, rather than certain and universal.
"Postmodernism is 'post' because it is denies the existence of any ultimate principles, and it lacks the optimism of there being a scientific, philosophical, or religious truth which will explain everything for everybody - a characterisitic of the so-called 'modern' mind. The paradox of the postmodern position is that, in placing all principles under the scrutiny of its skepticism, it must realize that even its own principles are not beyond questioning. As the philospher Richard Tarnas states, postmodernism 'cannot on its own principles ultimately justify itself any more than can the various metaphysical overviews against which the postmodern mind has defined itself.'" (emphases mine)
A postmodernist believes there are no absolute truths and that everything is relative. But that is a self-refuting statement. A postmodernist absolutely states that there are no absolutes. Can a postmodernist be skeptical of his belief in being skeptical? He can't have a belief and be skeptical at the same time. Postmodernism as a philosophy can't work.
J.P. Moreland, a well know Christian thinker discussed postmodernism in the webzine Boundless. Read his article Postmodernism and the Christian Life.
Postmodernism vanquished by the Secret Agent Librarian.