Exploring the central ideas of traditional metaphysics--such as the simplicity of nature, its comprehensibility, or its systematic integrity--this book analyzes looking at such notions from a scientific point of view. It seeks to describe in a clear, accessible manner the metaphysical situation that characterizes the process of inquiry in natural science, aiming to shed light on reality by examining the modus operandi of natural science itself and focusing as much on its findings as on its conceptual and methodological presuppositions. Written by an eminent scholar of philosophy, this book is the culmination of many years of penetrating work. It is the definitive presentation of some of Nicholas Rescher's most fascinating ideas and is an engaging source for philosophers and non-philosophers alike.