Originally published in 1964. This book is concerned with general arguments, by which is meant broadly arguments that rely for their force on the ideas expressed by all, every, any, some, none and other kindred words or phrases. A main object of quantificational logic is to provide methods for evaluating general arguments. To evaluate a general argument by these methods we must first express it in a standard form. Quantificational form is dealt with in chapter one and in part of (...) chapter three; in the remainder of the book an account is given of methods by which arguments when formulated quantificationally may be tested for validity or invalidity. Some attention is also paid to the logic of identity and of definite descriptions. Throughout the book an attempt has been made to give a clear explanation of the concepts involved and the symbols used; in particular a step-by-step and partly mechanical method is developed for translating complicated statements of ordinary discourse into the appropriate quantificational formulae. Some elementary knowledge of truth-functional logic is presupposed. (shrink)

This is partly a verbal question, depending on the meaning of the word ‘caste’. I propose to assume that if we say that a State is a caste State we imply at least two things: that its members are divided into mutually exclusive endogamous classes, and that no one may be transferred from one class to another—unless possibly to a lower class. The State which Plato describes in the Republic satisfies the first of these conditions. Dr. Popper, who believes that (...) it is a caste State, maintains that it also satisfies the second. In addition he contends that the original basis of the class division is racial. My object in the notes which follow is to argue that both these contentions are false. (shrink)