Logic Philosophy 18 Early works to 1800 15 History 13 Knowledge, Theory of 13 Reasoning 12 Methodology 10 Congresses 9 Science 9 Language and languages 8 Thought and thinking 8 Grammar, Comparative and general 5 Logic, Symbolic and mathematical 5 Semantics 5 Semantics (Philosophy) 5 Probabilities 4 Dialectic 3 Ethics 3 Judgment (Logic) 3 Mathematics 3 Ontology 3 Problems, exercises, etc 3 Values 3 Artificial intelligence 2 Buddhist logic 2 Communication 2 Empiricism 2 Generative grammar 2 Hindu logic 2 Idealism 2