ABSTRACT
Languages have two main kinds of rule: rules of structure or formation and rules of meaning. This chapter examines some of the logically important features of our everyday uses of certain key words, with a view to showing how the stressing of different features may lead to these various systems of logic. Modern logic was developed largely with the aim of achieving greater generality and rigour but also with the aim of avoiding some of the problems and ambiguities of the traditional logic. The chapter shows that the validity of deductive arguments used in everyday discourse depends mainly on the correct use of certain key words. Various systems of symbolic logic are possible and have been constructed. Various types of relation have been regarded as important bases for inference and a system of logic may be designed to explore one or other of these.
