MEMORABILIA MATHEMATICA THE MACMILLAN COMPANY NEW YORK. BOSTON. CHICAGO. DALLAS ATLANTA. SAN FRANCISCO MACMILLAN & CO., LIMITED LONDON. BOMBAY. CALCUTTA MELBOURNE THE MACMILLAN CO. OF CANADA, LTD. TORONTO MEMORABILIA MATHEMATICA OR THE PHILOMATH’S QUOTATION-BOOK BY ROBERT EDOUARD MORITZ, PH. D., PH. N. D. PROFESSOR OF MATHEMATICS IN THE UNIVERSITY OF WASHINGTON New York THE MACMILLAN COMPANY 1914 _All rights reserved_ COPYRIGHT, 1914, BY ROBERT EDOUARD MORITZ PREFACE Every one knows that the fine phrase “God geometrizes” is attributed to Plato, but few know where this famous passage is found, or the exact words in which it was first expressed. Those who, like the author, have spent hours and even days in the search of the exact statements, or the exact references, of similar famous passages, will not question the timeliness and usefulness of a book whose distinct purpose it is to bring together into a single volume exact quotations, with their exact references, bearing on one of the most time-honored, and even today the most active and most fruitful of all the sciences, the queen-mother of all the sciences, that is, mathematics. It is hoped that the present volume will prove indispensable to every teacher of mathematics, to every writer on mathematics, and that the student of mathematics and the related sciences will find its perusal not only a source of pleasure but of encouragement and inspiration as well. The layman will find it a repository of useful information covering a field of knowledge which, owing to the unfamiliar and hence repellant character of the language employed by mathematicians, is peculiarly inaccessible to the general reader. No technical processes or technical facility is required to understand and appreciate the wealth of ideas here set forth in the words of the world’s great thinkers. No labor has been spared to make the present volume worthy of a place among collections of a like kind in other fields. Ten years have been devoted to its preparation, years, which if they could have been more profitably, could scarcely have been more pleasurably employed. As a result there have been brought together over one thousand more or less familiar passages pertaining to mathematics, by poets, philosophers, historians, statesmen, scientists, and mathematicians. These have been gathered from over three hundred authors, and have been grouped under twenty heads, and cross indexed under nearly seven hundred topics.