ABSTRACT
1.1. Purpose of book. The purpose of the present book is to give such an account of Mathematical Logic as will make clear in the framework of its history some of the chief directions of its ideas and teachings. It is these directions, not the mass of detail forming the theory and its history, which are important for the rest of philosophy and are important, in addition, from the point of view of a general education. In the limits of our space we are able to give attention only to what has been, or seems as if it may be, fertile or of special value in some other way. More than this, Mathematical Logic having no small number of important developments, a selection of material is necessary, the selection being guided by the rule to take up the simpler questions, other things being roughly equal. Facts have to be looked at in the light of one’s purpose. Though they may all have the same value simply as facts, they are not at all equal as judged by the profit and the pleasure that thought, and not least the thought of the learner, is able to get from them.
