"World hypotheses" correspond to metaphysical systems, and they may be systematically judged by the canons of evidence and corroboration.

In setting forth his root-metaphor theory and examining six such hypotheses--animism, mysticism, formism, mechanism, contextualism, and organicism--Pepper surveys the whole field of metaphysics. Because this book is an analytical study, it stresses issues rather than men. It seeks to exhibit the sources of these issues and to show that some are unnecessary; that the rest gather into clusters and are interconnected in systems corresponding closely to the...