Introduction to Volume 4 -- 1 Logic of History (691) -- 2 [Parts of Carnegie Application] (L 75) -- 3 Fermatian Inference and DeMorgan's Syllogism of Transposed Quantity -- A. The Conception of Infinity (819) -- B. Fermatian Inference (820) -- C. The Critic of Arguments (589) -- 4 Logico-Mathematical Glosses (812) -- 5 Qualitative Logic: Preface -- The Modus Ponens -- The Logical Algebra of Boole (736) -- 6 Meaning (Pragmatism) (622) -- 7 Abstracts of Eight Lectures [Topological Basis of Philosophy of Continuity] (942) -- 8 Lectures on Pragmatism, Lecture II (302, 303) -- 9 Types of Reasoning (441) -- 10 Reason's Conscience -- A Practical Treatise on the Theory of Discovery Wherein Logic Is Conceived as Semeiotic (parts of six notebooks in 693) -- 11 An Appraisal of the Faculty of Reasoning (616, 617) -- 12 [Necessary Reasoning] (760) -- 13 Of the Place among the Sciences of Philosophy and of each Branch of it (from 328) -- 14 Καινὰ στοιχεῖα (517) -- 15 On Quantity with Special Reference to Collectional and Mathematical Infinity (15) -- 16 A. Sketch of Dichotomic Mathematics (4) -- B. On the Number of Dichotomous Divisions -- a Problem in Permutations (74) -- 17 The Categories (717) -- 18 (PAP) (293) -- 19 Detached Ideas Continued and the Dispute Between Nominalists and Realists (439) -- 20 [The Problem of Map Coloring] (154) -- 21 How to Reason: A Critick of Arguments (397) -- 22 On Physical Geometry (257) -- 23 Methods of Reasoning (748) -- 24 Sketch of a New Philosophy (928) -- 25 [Conceptions of Modern Mathematics] (from 950) -- Key to Greek Terms -- Index of Names -- Subject Index.