Existentialism along with Pragmatism are the precursers of Post-Modernism. Though this book was written in the early 1960's Robert G. Olson's book gives a fairly complete summary and history of Existentialist philosophy. It compares it to Rationalism, Empiricism and Pragmatism in Epistimology, as well as Realism and Idealism in Metaphysics. Olson also covers many of the Ethical implications of Existentialism. He juxtiposes it to "Modern" Analytic Philosophy. I enjoyed this book immensely because I like comparing rival ideas and Philosophies. If you're interested in that too, or just want to understand the roots of Post-Modernism, or the way some European intelectuals think, then you should find this to be a great book.