STATISTICS and PROBABILITY) should not be lost sight of ; the leading fields for these applications are insurance, sociology, varia tion in zoology and economics.
1908). Also the following works are of importance, though not all expressly expounding the Leibnitzian point of view: cf. G. Cantor, "Grundlagen einer allgemeinen Mannigfaltigkeitslehre," Math. Annal., vol. xxi. (1883) and subsequent articles in vols. xlvi. and xlix.; also R. Dedekind, Stetigkeit and irrationale Zahlen (1st ed., 1872), and Was sind and was sollen die Zahlen? (1st ed., 1887), both tracts translated into English under the title Essays on the Theory of Numbers (Chicago, 1901). These works of G. Cantor and Dedekind were of the greatest importance in the progress of the subject. Also cf. G. Peano (with various collaborators of the Italian school), Formulaire de mathematiques (Turin, various editions, 1894-1908; the earlier editions are the more interesting philosophically) ; Felix Klein, Lectures on Mathematics (New York, 1894) ; W. K. Clifford, The Common Sense of the exact Sciences (London, 1885) ; H. Poincare, La Science et l'hypothese (Paris, ist ed., 1902), English translation under the title, Science and Hypothesis (London, 1905) ; L. Couturat, Les Principes des mathematiques (Paris, 1905) ; E. Mach, Die Mechanik in ihrer Entwickelung (Prague, 1883), English trans lation under the title, The Science of Mechanics (London, 1893) K. Pearson, The Grammar of Science (London, 1st ed., 1892 ; and ed., 1900, enlarged) ; A. Cayley, Presidential Address (Brit. Assoc., 1883) ; B. Russell and A. N. Whitehead, Principia Mathematica (Cambridge, 1911). (A. N. W.)