His third large work--his greatest book--L'Evolution creatrice, appeared in 1907, and is undoubtedly, of all his works, the one which is most widely known and most discussed. It constitutes one of the most profound and original contributions to the philosophical consideration of the theory of Evolution. Un livre comme L'Evolution creatrice, remarks Imbart de la Tour, n'est pas seulment une oeuvre, mais une date, celle d'une direction nouvelle imprimee a la pensee. By 1918, Alcan, the publisher, had issued twenty-one editions, making an average of two editions per annum for ten years. Since the appearance of this book, Bergson's popularity has increased enormously, not only in academic circles, but among the general reading public. He came to London in 1908 and visited William James, the American philosopher of Harvard, who was Bergson's senior by seventeen years, and who was instrumental in calling the attention of the Anglo-American public to the work of the French professor. This was an interesting meeting and we find James' impression of Bergson given in his Letters under date of October 4, 1908. "So modest and unpretending a man but such a genius intellectually! I have the strongest suspicions that the tendency which he has brought to a focus, will end by prevailing, and that the present epoch will be a sort of turning point in the history of philosophy." As in some quarters erroneous ideas prevail regarding both the historical and intellectual relation between James and Bergson, it may be useful to call attention to some of the facts here. As early as 1880 James contributed an article in French to the periodical La Critique philosophique, of Renouvier and Pillon, entitled Le Sentiment de l'Effort.[Footnote: Cf. his Principles of Psychology, Vol. II., chap xxvi.] Four years later a couple of articles by him appeared in Mind: What is an Emotion?[Footnote: Mind, 1884, pp. 188-205.] and On some Omissions of Introspective Psychology.[Footnote: Mind, 1884, pp. 1-26.] Of these articles the first two were quoted by Bergson in his work of 1889, Les donnees immediates de la conscience. In the following years 1890-91 appeared the two volumes of James' monumental work, The Principles of Psychology, in which he refers to a pathological phenomenon observed by Bergson. Some writers taking merely these dates into consideration, and overlooking the fact that James' investigations had been proceeding since 1870, registered from time to time by various articles which culminated in The Principles, have mistakenly assigned to Bergson's ideas priority in time.[Footnote: For example A. Chaumeix: William James (Revue des Deux Mondes, Oct, 1910), and J. Bourdeau: Nouvelles modes en philosophie, Journal de Debats, Feb., 1907. Cf. Flournoy: La philosophie de William James. (Eng. Trans. Holt and James, pp. 198-206).] On the other hand insinuations have been made to the effect that Bergson owes the germ-ideas of his first book to the 1884