The Classical Logical Calculus

Abstract

Logic selects inference methods used in science and considered to be correct, and then constructs logical systems on them. These systems are sets of various laws and rules which, when followed, yield all the inferences we can immediately accept. There is perfect agreement in mathematics as to which methods of inference are acceptable and which are not. It does not happen that some people consider some rules of inference to be correct, while others consider them to be entirely wrong. There are only slight differences of opinion about the meaning of some rules and about the extent of their applicability. The set of almost all the methods of inference that are used in mathematics is called classical logic.