Two men, it seems, have said everything worth saying in English. If the language is archaic, it was said by Shakespeare. If modern, it is usually attributed to Mark Twain. "A quotation," Twain said once, "is the act of repeating erroneously the words of another." And, I might add, the mistaken attribution of such words. This is the sort of wry, dry wit that was Twain's hallmark. Too bad he never said it.
Ambrose Bierce is responsible for some of the most frequently quoted sallies of wit ever produced in English, usually ascribed to someone else. Most of these were published in a newspaper column titled "The Devil's Dictionary", appearing at odd intervals from 1881 to 1906. Some of my favorites include:
In 1911, a comprehensive collection was printed under its present title, with a preface by the author. The book contains mainly a large number of definitions similar to those quoted above, humorous verses, and some delightful stories. Some of the matter is dated in terms of historical context, but most of the text is quite accessible, and will impress the reader with a sense of how little people have really changed in almost a century.
The book is still in print, and is also accessible from the web. However, I feel obliged to issue this caveat: after reading the book, you may experience a maddening appreciation of wit, and an irresistible urge to speak and write in clean, literate English. The compulsion is usually transient.