This volume covers the period from the beginning of Russell's work on Volume Two of the Principles of Mathematics to the critical discovery of the theory of descriptions in 1905. Foundations of Logic gives a vivid picture of Russell wrestling with the logical paradoxes, often unsuccessfully, as he tries out one foundational scheme after another.

This volume provides the key to both Bertrand Russell's philosophy of logic and philosophy of mathematics. It includes unpublished work on the theory of denoting which predates Russell's famous article of 1905 and unpublished manuscripts on the so-called "zig-zag" theory with which Russell attempted to provide a type-free foundation for mathematics. The volume also gathers together for the first time a number of reviews and survey articles, along with two talks on modality and truth. It will be an essential addition to any Bertrand Russell collection.