This book repairs and revives the Theory of Knowledge research program of Russell’s Principia era. Chapter 1, 'Introduction and Overview', explains the program’s agenda. Inspired by the non-Fregean logicism of Principia Mathematica, it endorses the revolution within mathematics presenting it as a study of relations. The synthetic a priori logic of Principia is the essence of philosophy considered as a science which exposes the dogmatisms about abstract particulars and metaphysical necessities that create prisons that fetter the mind. Incipient in The Problems of Philosophy, the program’s acquaintance epistemology embraced a multiple-relation theory of belief. It reached an impasse in 1913, having been itself retrofitted with abstract particular logical forms to address problems of direction and compositionality. With its acquaintance epistemology in limbo, Scientific Method in Philosophy became the sequel to Problems. Chapter 2 explains Russell’s feeling intellectually dishonest. Wittgenstein’s demand that logic exclude nonsense belief played no role. The 1919 neutral monist era ensued, but Russell found no epistemology for the logic essential to philosophy. Repairing, Chapters 4–6 solve the impasse. Reviving, Chapters 3 and 7 vigorously defend the facts about Principia. Studies of modality and entailment are viable while Principia remains a universal logic above the civil wars of the metaphysicians.

Wittgenstein’s May–June 1913 critique of Russell’s multiple-relation theory of judgement (or MRTJ) marked a crucial turning point in the lives of two great twentieth-century thinkers. It was also a watershed moment within the history of analytic philosophy itself. Yet scholarly consensus around a satisfactory interpretation of the nature of the critique, the extent of and reasons for its impact on Russell, along with the role it played within Wittgenstein’s development have remained elusive. With these facts in mind, this book aims to accomplish four interrelated goals. The first is to develop a compelling reading of Wittgenstein’s May–June 1913 critique of Russell’s MRTJ. The second is to defend this reading, called the ‘logical interpretation’ (or LI) against its most prominent competitors in the scholarly literature. Third, the book aims to situate Wittgenstein’s critique of the MRTJ and Russell’s reaction to it, within the broader context of each of Wittgenstein’s and Russell’s respective philosophical developments. Fourth and finally, the book aims to introduce students and scholars of early analytic philosophy to, and familiarize them with the historical events, textual evidence, scholarly controversies, letters, notes and diagrams, consideration of which is integral to constructing a plausible reading of Wittgenstein’s objection.

This volume provides a historical introduction in the writing of the manuscript. Theory of Knowledge: The 1913 Manuscript is the only book-length work on epistemology that Russell left unpublished in its original form, and its publication here is an important addition to knowledge of Russell's thought.

Theory of Knowledge gives us a picture of one of the great minds of the twentieth century at work. It is possible to see the unsolved problems left without disguise or evasion. Historically, it is invaluable to our understanding of both Russell's own thought and his relationship with Wittgenstein.