through the medium of a developed organism, “an internal push that has carried life by more and more complex forms, to higher and higher destinies.”  It is a dynamic continuity, a continuity of qualitative progress, a duration which leaves its bite on things. [Footnote:  For these descriptions of life, see Creative Evolution, pp. 27-29 and 93-94 (Fr. pp. 28-30 and 95-96).] We shall be absolutely wrong, however, if we attempt to view the evolutionary process as progressive in a straight line.  The facts contradict such a facile and shallow view.  Some of the stock phrases of the earlier writers on Evolution were:  “adaptation to environment,” “selection” and “variation,” and a grave problem was presented by this last.  How are we to account for the variations of living beings, together with the persistence of their type?  Herein lies the problem of the origin of species.  Three different solutions have been put forward.  There is the “Neo-Darwinian” view which attributes variation to the differences inherent in the germ borne by the individual, and not to the experience or behaviour of the individual in the course of his existence.  Then there is the theory known as “Orthogenesis” which maintains that there is a continual changing in a definite direction from generation to generation.  Thirdly, there is the “Neo-Lamarckian” theory which attributes the cause of variation to the conscious effort of the individual, an effort passed on to descendants. [Footnote:  Concerning Lamarck (1744-1829) Bergson remarks in La Philosophie (1915) that without diminishing Darwin’s merit Lamarck is to be regarded as the founder of evolutionary biology.] Now each one of these theories explains a certain group of facts, of a limited kind, but two difficulties confront them.  We find that on quite distinct and widely separated lines of Evolution, exactly similar organs have been developed.  Bergson points out to us, in this connexion, the Pecten genus of molluscs, which have an eye identical in structure with that of the eye of vertebrates. [Footnote:  The common edible scallop (Pecten maximus) has several eyes of brilliant blue and of very complex structure.] It is obvious, however, that the eye of this mollusc and the eye of the vertebrate must have developed quite independently, ages after each had been separated from the parent stock.  Again, we find that in all organic evolution, infinite complexity of structure accompanies the utmost simplicity of function.  The variation of an organ so highly complex as the eye must involve the simultaneous occurrence of an infinite number of variations all co-ordinated to the simple end of vision.  Such facts as these are incapable of explanation by reference to any or all of the three theories of adaptation and variation mentioned.  Indeed they seem capable of explanation only by reference to a single original impetus retaining its direction in courses far removed from the common origin.  “That adaptation to environment is the necessary condition of Evolution we do not question for a moment.  It is quite evident that a species would disappear, should it fail to bend to the conditions of existence which are imposed on it.  But it is one thing to recognize that outer circumstances are forces Evolution must reckon with, another to claim that they are the directing causes of Evolution.” [Footnote:  Creative Evolution, p. 107 (Fr. p. 111).]