Symbolic Logic [antikvár]

PREFACE TO THIRD EDITION The third edition of Symbolic Logic diflfers from the second in several minor respects and one major respect. Some of the minor revisions involve mere changes in wording for greater clarity. The major change is due to Professor William Tuthill Parry, who discovered that the quantification rules set forth in Chapter 4 of the second edition were incorrect.^ Those rules were originally published early in 1956,^ and appeared to offer some advantages in simplicity and ease of application over the quantification rules presented in the first edition of this book. When no objections to them had come to my attention by the end of 1964, I decided to include them in the second edition, which was published in the spring of 1965. Its appearance was followed shortly by the publication of Professor Parry's article. ' William Tuthill Parry, 'Comments on a Variant Form of Natural Deduction', The Journal of Symbolic Logic, vol. 30 (June 1965), pp. 119-122. See also Hugues Leblanc, 'Minding One's A"s and K's', Logique et Analyse (September 1965), and John G. Slater's 'The Required Correction to Copi's Statement of UG', Logique el Analyse (June 1966). ^ Irving M. Copi, 'Another Variant of Natural Deduction', The Journal of Symbolic Logic, vol. 21 (March 1956), pp. 52-55. iii