First published in 2000. This is Volume II of six in the Library of Philosophy series on the Philosophy of Science. Written in 1938, philosophical systems which employ logical methods almost exclusively would undoubtedly be expected to produce non-empirical results. If, however, logic is taken simply as a method of connecting meanings it is not difficult to reconcile logical methods with empirical results. If logical formular, in other words, assert nothing about the meanings of propositions, but simply show how such meanings are connected, then an empiricism based on a logical analysis of meanings is not inconsistent. This is what the Logical Positivists have attempted to do. This book looks at two areas: the foundations of a scientific method free from metaphysics, and the elimination of pseudo-concepts introduced by metaphysics into science and philosophy.