Excerpt from Symbolic Logic Elementary, Vol. 1
The chief alterations, in this Edition, have been made in the Chapter on 'Classification' (pp. 2, 3) and the Chapter on 'Propositions of Existence' (pp. 12, 13).
In the first of these I have adopted a new definition of the Process, which enables me to regard the whole Universe as a 'Class', and thus to dispense with the very awkward phrase 'a Set of Things.'
In the second, I have adopted a new 'normal form,' in which the Class, whose existence is affirmed or denied, is regarded as the Predicate, instead of the Subject, of the Proposition, thus evading a very subtle difficulty which besets the other form. These subtle difficulties seem to lie at the root of every Tree of Knowledge, and they far more hopeless to grapple with than any that occur in its higher branches. For example, the difficulties of the Forty-Seventh Proposition of Euclid are mere child's play compared with the mental torture endured in the effort to think out the essential nature of a straight Line. And, in the present work, the difficulties of the "5 Liars" Problem, at p. 188, are "trifles, light as air," compared with the bewildering question "What is a Thing?"
Besides these alterations, I have corrected a number of misprints, some of which have been pointed to me by friends - but none of my critics have been sharp-eyed enough to detect the splendid misprint at p. 109, where the following Trio of Propositions is proposed as a Syllogism: -
"A prudent man shuns hy?nas;
Anything but gold will fail to silence him.
No banker fails to shun hy?nas."
About the Publisher
Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com
This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works. Это и многое другое вы найдете в книге Symbolic Logic Elementary, Vol. 1 (Classic Reprint) (Lewis Carroll)