Introduction

This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book provides an elementary introduction to logical systems and to some of the central problems of logical theory. It presents the logic of terms and the logic of propositions as complementary parts of one branch of study. The book provides a brief and incomplete account of some kinds of thinking which only indirectly concern the formal logician. For the student of a hundred years ago elementary formal logic consisted of the syllogistic logic of Aristotle, modified and added to in the middle ages, but already for centuries stereotyped and unchallenged. It provided material for exercises in the application of rules learnt by heart, but it does not seem to have stimulated thought or intellectual curiosity. The revival of logic and the widening of its scope have not only brought new discoveries but have also led to the critical re-examination of traditional doctrines.