Logic

Excerpt from the Preface: A word now as to the general plan and contents of this book. There are three parts, each of which discusses and indispensable aspect of the enterprise of rational thinking. The careful thinker will be interested in language, the instrument of thinking; in the soundness of his arguments; and in the truth of his assertions. Part One is concerned with linguistic and semantical problems; in Part Two we shall discuss the principles of valid inference or sound reasoning; and in Part Three we shall examine the methods employed by the sciences of nature and society, seeking to determine the methods whereby these disciplines attempt to furnish us with logically justifiable beliefs.