Can we justify our most basic beliefs about morality, religion and the nature of the world? Can there be a rational and objective way of choosing between alternative societies, modes of life or world-views? Dr Trigg shows how philosophical analysis is relevant to these questions and criticizes the tendency to emphasize notions of commitment and convention at the expense of truth and reason. He draws parallels between issues that are often too isolated from each other and identifies a cluster of related ideas, all of which stress the notion of self-contained conceptual systems that define their own standards of rationality. First published in 1973, this book will interest professional philosophers as a vigorous and distinctive exposition of several fundamental philosophical problems and more especially it can be used as an introduction for students to a wide range of philosophical problems.