NOTE, September, 2021: This is the corrected second eBook edition of this work. Readers are asked to use this edition. The _Critique of Impure Reason_ has now also been published in a printed edition. To reduce the otherwise high price of this scholarly/technical book of nearly 900 pages and make it more widely available beyond university libraries to individual readers, the non-profit publisher and the author have agreed to issue the printed edition at cost. The printed edition was released on September 1, 2021 and is now available through all booksellers, including Barnes & Noble, Amazon, and brick-and-mortar bookstores under the following ISBN: 978-0-578-88646-6 Commendations of this work, from the back cover of the published edition: “I admire its range of philosophical vision.” – Nicholas Rescher, Distinguished University Professor of Philosophy, University of Pittsburgh, author of more than 100 books. “Bartlett’s _Critique of Impure Reason_ is an impressive, bold, and ambitious work. Careful scholarship is balanced by original analyses that lead the reader to recognize the limits of meaning, knowledge, and conceptual possibility. The work addresses a host of traditional philosophical problems, among them the nature of space, time, causality, consciousness, the self, other minds, ontology, free will and determinism, and others. The book culminates in a fascinating and profound new understanding of relativity physics and quantum theory.” – Gerhard Preyer, Professor of Philosophy, Goethe-University, Frankfurt am Main, Germany, author of many books including _Concepts of Meaning_, _Beyond Semantics and Pragmatics_, _Intention and Practical Thought_, and _Contextualism in Philosophy_. “[This work’s] goal is of a unique and difficult species: Dr. Bartlett seeks to develop a formal logical calculus on the basis of transcendental philosophical arguments; in fact, he hopes that this calculus will be the formal expression of the transcendental foundation of knowledge.... I consider Dr. Bartlett’s work soundly conceived and executed with great skill.” – C. F. von Weizsäcker, philosopher and physicist, former Director, Max-Planck-Institute, Starnberg, Germany. “Bartlett has written an American “Prolegomena to All Future Metaphysics.” He aims rigorously to eliminate meaningless assertions, reach bedrock, and place philosophy on a firm foundation that will enable it, like science and mathematics, to produce lasting results that generations to come can build on. This is a great book, the fruit of a lifetime of research and reflection, and it deserves serious attention.” — Martin X. Moleski, former Professor, Canisius College, Buffalo, NY, studies of scientific method, the presuppositions of thought, and the self-referential nature of epistemology. “Bartlett has written a book on what might be called the underpinnings of philosophy. It has fascinating depth and breadth, and is all the more striking due to its unifying perspective based on the concepts of reference and self-reference.” – Don Perlis, Professor of Computer Science, University of Maryland, author of numerous publications on self-adjusting autonomous systems and philosophical issues concerning self-reference, mind, and consciousness. +++++++++++++++++++++++++++++++++++++++++ The _Critique of Impure Reason: Horizons of Possibility and Meaning_ comprises a major and important contribution to the philosophy of science. Thanks to the generosity of its publisher, this massive volume of 885 pages has been published as a free open access eBook. It inaugurates a revolutionary paradigm shift in philosophical thought by providing compelling and long-sought-for solutions to a wide range of problems that have concerned philosophers of science as well as epistemologists. The book includes a Foreword by the celebrated German physicist and philosopher of science Carl Friedrich von Weizsäcker. The principal objective of the study is to identify the unavoidable limitations of the conceptual frameworks in terms of which knowledge, reference, and meaning are possible. The book establishes a bridge between, on the one hand, a model of philosophy as a science — i.e., rigorous proof-based scientific philosophy — and, on the other, the philosophy of science. The study develops a logically compelling method that enables us both to recognize the boundaries of what is referentially forbidden — the limits beyond which reference becomes meaningless — and second, to avoid falling victims to a certain broad class of conceptual confusions which lie at the heart of major problems of philosophy of science and epistemology. With these ends in view, individual chapters are devoted to a critique of a wide range of fundamental concepts studied by philosophy of science, among them, space, time, space-time, causality, the problem of discovery or invention in general problem-solving, mathematics, and physics, the role of the observer, the perturbation theory of measurement, indeterminacy and uncertainty, complementarity, the ontological status of physical reality, and others. The study culminates in a group of chapters devoted to special and general relativity and quantum theory. In these concluding chapters the purpose is to show the extent to which both relativity physics and quantum theory bear out results that have been reached in a logically compelling manner wholly by means of the approach to conceptual analysis developed in the book. Based on original research and rigorous analysis combined with extensive scholarship, the _Critique of Impure Reason_ develops a logically self-validating method that at last provides provable and constructive solutions to a significant number of major philosophical problems in philosophy of science and epistemology. Bartlett is the author or editor of more than 20 books and numerous papers.