Question as to the "father of Logic"--Socrates, Plato, Aristotle --Enquiries as to the nature of the concept in Greece. Question of transcendency and immanence--Controversies in Plato concerning the various forms of the concept--Philosophic, empirical and abstract concepts in Aristotle. Philosophy, physics, mathematics--Universals of the "always" and those of "for the most part"--Logical controversies in the Middle Ages--Nominalism and realism--Nominalism, mysticism and coincidence of opposites--Renaissance and mysticism--Bacon--Ideal of exact science and Cartesian philosophy--Adversaries of Cartesianism --Vico--Empiristic logic and its dissolution. Locke, Berkeley and Hume--Exact science and Kant. Concept of the category--Limits of science, and Jacobi--Positive elements in Kantian scepticism--The synthesis _a priori_--Inward contradiction in Kant. Romantic principle and classic execution--Progress since Kant: Fichte, Schelling, Hegel--Logic of Hegel. The concrete concept or Idea--Identity of Hegelian Idea and Kantian synthesis _a priori_--The Idea and the antinomies. The dialectic--Lacunæ and errors in Hegelian Logic. Their consequences--Contemporaries of Hegel: Herbart, Schleiermacher and others--Posterior positivism and psychologicism--Eclectics. Lotze--New gnoseology of the sciences. Economic theory of scientific concept. Avenarius, Mach--Rickert--Bergson and the new French philosophy--Le Roy, and others--Reattachment to romantic ideas, and progress upon them--Philosophy of pure experience, of intuition, of action, etc.: and its insufficiency--The theory of values. III THEORY OF THE INDIVIDUAL JUDGMENT Secular neglect of theory relating to history--Ideas upon history in Græco-Roman world--Theory of history in mediæval and modern philosophy--Writers on historical art in the sixteenth century--Writers on method--Theory of history and G. B. Vico--Anti-historicism of eighteenth century, and Kant--Hidden historical value of synthesis _a priori_--Theory of history in Hegel--W. von Humboldt--F. Brentano--Controversies as to the nature of history--Rickert; Xénopol. History as science of individual--History as art--Other controversies relating to history. IV THEORY OF THE RELATIONS BETWEEN THOUGHT AND WORD AND FORMALIST LOGIC Relation between history of Logic and history of Philosophy of language--Logical formalism. Indian logic free of it--Aristotelian Logic and formalism--Later formalism--Rebellions against Aristotelian Logic--Opposition by humanists and its motives--Opposition of naturalism--Simplicatory elaboration in eighteenth century. Kant--Refutation of formal Logic. Hegel; Schleiermacher--Its partial persistence, owing to insufficient ideas as to language--Formal Logic in Herbart, in Schopenhauer, in Hamilton--More recent theories--Mathematical Logic--Inexact idea of language among mathematicians and intuitionists. V CONCERNING THIS LOGIC