Elements of arithmetic

BY AUGUSTUS DE MORGAN,
OF TRINITY COLLEGE, CAMBRIDGE;
FELLOW OF THE ROYAL ASTRONOMICAL SOCIETY, AND OF THE CAMBRIDGE PHILOSOPHICAL SOCIETY; PROFESSOR OF MATHEMATICS IN UNIVERSITY COLLEGE, LONDON.
“Hominis studiosi est intelligere, quas utilitates proprie afferat arithmetica his, qui solidam et perfectam doctrinam in cæteris philosophiæ partibus explicant. Quod enim vulgo dicunt, principium esse dimidium totius, id vel maxime in philosophiæ partibus conspicitur.”—Melancthon.
“Ce n’est point par la routine qu’on e’instruit, c’est par sa propre réflexion; et il est essentiel de contracter l’habitude de se rendre raison de ce qu’on fait: cette habitude s’acquiert plus facilement qu’on ne pense; et une fois acquise, elle ne se perd plus.”—Condillac.
SEVENTEENTH THOUSAND.
LONDON: WALTON AND MABERLY, UPPER GOWER STREET, AND IVY LANE, PATERNOSTER ROW.
M.DCCC.LVIII.
LONDON: PRINTED BY J. WERTHEIMER AND CO., CIRCUS-PLACE, FINSBURY-CIRCUS.
At the time when this work was first published, the importance of establishing arithmetic in the young mind upon reason and demonstration, was not admitted by many. The case is now altered: schools exist in which rational arithmetic is taught, and mere rules are made to do no more than their proper duty. There is no necessity to advocate a change which is actually in progress, as the works which are published every day sufficiently shew. And my principal reason for alluding to the subject here, is merely to warn those who want nothing but routine, that this is not the book for their purpose.
A. De Morgan.
London, May 1, 1846.