word is now generally understood and as it has been understood throughout this work. The Formation of Terms is a subject which properly belongs to Psychology and not to Logic, and moreover could not be adequately treated in a small compass. It is true that some questions properly belonging to Psychology or the History of Logic have been noticed in various parts of the book, but they have only been casually alluded to, not treated in distinct chapters. Logic has always been over-weighted with extraneous matter, and, wherever it is possible, it is desirable to relieve it of its superfluities, though much discretion may be needed in the process, and though the requirements of examinations have a constant tendency to lead writers on Logic to consider not how little, but how much they can introduce into their works. In the Fifth and subsequent Editions, the Author has added an Appendix on the Heads of Predicables. There is no branch of elementary Logic so difficult to state in a form at once satisfactory to the teacher and intelligible to the learner. The attempt at a scientific treatment which he has made in Pt. II. ch. v. is, he believes, usually found too complicated for a beginner. As, however, he cannot state his own view of the doctrine in a simpler form, he has thought it the best course to add an Appendix, which, without any attempt at an exhaustive treatment, simply offers an explanation of the five words, Genus, Species, Differentia, Property, Accident. This Appendix, on the first reading of the book, may be substituted by the student for Pt. II. ch. v., but should be combined with the formal definitions given on p. 46, of which, in fact, it furnishes an explanation. The principal changes in the eighth Edition were the addition of notes to Pt. III. chs. i. and vii., and some alterations in the text of the latter part of ch. vii. ; in the ninth Edition, certain additions to the latter part of ch. vii. and to the foot-note on p. 73 [now 75]. In the present Edition, the principal changes are an addition to note I on p. 19, the addition of a note on p. 21, some changes of language on pp. 26, 27 and pp. 70, 71, an addition on the Law of Identity to note 3, p. 75, and the addition of a new paragraph on the unsatisfactory character of the Dilemma, as a practical argument, on p. 123. |