definable in abstract or conceptual terms, is declared to be one of the clearest facts established by observation. It is no doubt misleading to attempt to sum up a system of philosophy in a sentence, but perhaps some part of the spirit of Professor Bergson's philosophy may be gathered from the motto which, with his permission, I have prefixed to this translation:--"If a man were to inquire of Nature the reason of her creative activity, and if she were willing to give ear and answer, she would say--'Ask me not, but understand in silence, even as I am silent and am not wont to speak.'" F. L. POGSON. OXFORD, _June,_ 1910. BIBLIOGRAPHY I. WORKS BY BERGSON. (a) _Books._ Quid Aristoteles de loco senserit, (Thesis), Paris, 1889. Essai sur les données immédiates de la conscience, Paris, 1889, 1910⁷. Matière et Mémoire, Essai sur la relation du corps avec l'esprit, Paris, 1896, 1910⁶. Le Rire, Essai sur la signification du comique, Paris, 1900, 1910⁶. (First published in the _Revue de Paris,_ 1900, Vol. I., pp. 512-545 and 759-791.) L'Évolution créatrice, Paris, 1907, 1910⁶. (b) _Articles._ La Spécialité. (Address at the distribution of prizes at the lycée of Angers, Aug. 1882.) De la simulation inconsciente dans l'état d'hypnotisme. _Revue philosophique,_ Vol. 22, 1886, pp. 525-531. Le bon sens et les études classiques. (Address at the distribution of prizes at the "Concours général des lycées et collèges," 1895.) Mémoire et reconnaissance. (_Revue philos._ Mar., Apr. 1896, pp. 225-248 and 380-399. Republished in _Matière et Mémoire._) Perception et matière. (_Rev. de Mét. et de Mor._ May 1896, pp. 257-277. Republished in _Matière et Mémoire._) Note sur les origines psychologiques de notre croyance à la loi de causalité. (Lecture at the Philosophical Congress in Paris, 1900, published in the _Bibliothèque du Congrès International de Philosophie;_ cf. _Revue de Métaphysique et de Morale,_ Sept. 1900, pp. 655 ff.) Le Rêve. (Lecture at the _Institut psychologique international_: published in the _Bulletin de l'Institut psych. intern._ May 1901; cf. _Revue scientifique,_ 4e S., Vol. 15, June 8, 1901, pp. 705-713, and _Revue de Philosophie,_ June 1901, pp. 486-488.) Le Parallélisme psycho-physique et la métaphysique positive. _Bulletin de la Société française de Philosophie,_ June 1901. L'Effort intellectuel. _Revue philosophique,_ Jan. 1902. Introduction à la métaphysique. _Revue de Mét. et de Mor._ Jan. 1903. Le Paralogisme psycho-physiologique. (Lecture at the Philosophical Congress in Geneva, 1904, published in the _Revue de Mét. et de Mor._ Nov. 1904, pp. 895-908; see also pp. 1027-1036.) L'Idée de néant, _Rev. philos._ Nov. 1906, pp. 449-466. (Part of Chap. 4 of _L'Évolution créatrice._) Notice sur la vie et les œuvres de M. Félix Ravaisson-Mollien. (Lecture before the Académie des Sciences morales et politiques: published in the _Proceedings_ of the Academy, Vol. 25, pp. 1 ff. Paris, 1907.)