This antiquarian volume contains a detailed treatise on logic and the theory of 'Inquiry'. It is a development of ideas regarding the nature of logical theory that were first presented in 'Studies in Logical Theory'. The present work is marked in particular by application of the earlier ideas to interpretation of the forms and formal relations that constitute the standard material of the logical tradition. Inquiry is one of the most essential skills in the world of business and management; as well as being of great utility to the student of philosophy, this book can help clarify the process of inquiry and develop skills for inquiry in the context of decision making, and may therefore be of considerable service to a range of different readers. The chapters of this volume include: 'The Matrix of Inquiry', 'The Problem of Logical Subject-Matter', 'Common Sense and Scientific Inquiry', 'The Needed Reform of Logic', 'Immediate Knowledge: Understanding and Inference', et cetera. This vintage book is being republished now in an affordable, modern edition complete with a new prefatory biography of the author.