476 



NATURE 



[October 12, 191 1 



before. We are creating- ourselves continually." So 

 of an organism it may be said that "its past, in its 

 entirety, is prolonged into its present, and abides 

 there, actual and acting." 



"Continuity of change, preservation of the past in 

 the present, real duration — the living being seems, 

 then, to share these attributes with consciousness. 

 Can we go further and say that life, like conscious 

 activity, is unceasing activity?" 



Bergson answers this question by an emphatic 

 affirmative. The spontaneity of life is manifested by 

 a continual creation of new forms. 



Many biologists and others have previously ex- 

 pounded the idea of the organism as a historic being, 

 but Bergson has given it a new vividness. "Wher- 

 ever anything lives, there is, open somewhere, a 

 register in which time is being inscribed." For it is 

 of the essence of Bergson 's thinking that time has an 

 effective action and a reality of its own. 



"We perceive duration as a stream against which 

 we cannot go. It is the foundation of our being, 

 and, as we feel, the very substance of the world in 

 which we live." 



"The evolution of the living being, like that of the 

 embryo, implies a continual recording of duration, a 

 persistence of the past in the present, and so an 

 appearance, at least, of organic memory." 



It is this conception, in part, which leads Bergson 

 to reject radical mechanism with some emphasis, and, 

 for that matter, radical finalism as well, though he 

 ends with leaving us with a theory that partakes of 

 finalism to a certain extent. 



Prof. Bergson thinks of life as 

 " the continuation of one and the same impetus, 

 divided into divergent lines of evolution. Something 

 has grown, something has developed by a series of 

 additions which have been so many creations." 

 "Evolution has taken place through millions of indi- 

 viduals, on divergent lines, each ending at a crossing 

 from which new paths radiate, and so on indefinitely." 



He believes that the essential causes working along 

 these diverse roads are "of psychological nature." It 

 is to be expected therefore that " they should keep 

 something in common in spite of the divergence of 

 their effects." 



" Something of the whole, therefore, must abide in 

 the parts ; and this common element will be evident 

 to us in some way, perhaps by the presence of identical 

 organs in very different organisms." 



It is this idea which leads Prof. Bergson 

 to devote particular attention to the phenomenon 

 of convergence in evolution, to the occurrence, 

 for instance, of closely similar eyes in molluscs 

 and in vertebrates — eyes which differ greatly 

 in development, and must have had a quite inde- 

 pendent evolution. 



"What likelihood is there that, by two entirely 

 different series of accidents being added together, two 

 entirely different evolutions will arrive al similar 

 results? " 



Of course, the conventional Darwinian and 

 Lamarckian interpretations are carefully considered. 



" But such similarity of the two products would be 

 natural, on the contrary, on a hypothesis like ours : 

 even in the latest channel there would be something 

 NO. 2189, V0L - 8/] 



of the impulsion received at the source. Pure 

 mechanism, then, would be refutable, and finality, in 

 the special sense in which we understand it, would be 

 demonstrable in a certain aspect, if it coidd be proved 

 that life may manufacture the like apparatus, by un- 

 like means, on divergent lines of evolution ; and the 

 strength of the proof would be proportional both to 

 the divergency between the lines of evolution thus 

 chosen and to the complexity of the similar structures 

 found in them." 



This is one of the ingenious arguments of this 

 brilliant essay, but we doubt if it would convince 

 anyone against his will. 



Prof. Bergson considers various theories of evolu- 

 tion, which he regards as each true in its way. The 

 neo-Darwinians are probably right in teaching that 

 the essential causes of variation are the differences in 

 the germs borne by the individual, but probably wrong 

 in regarding (or if they regard) these differences as 

 purely accidental and individual. Eimer was probably 

 right to some extent in his idea of variation continu- 

 ing from generation to generation in definite direc- 

 tions, but probably wrong in his claim that combina- 

 tions of physical and chemical causes are enough to 

 secure the result. The neo-Lamarckians are probably 

 right in insisting on causes of a psychological nature, 

 but they are probably wrong in thinking merely of 

 the conscious effort of the individual and in assuming 

 the regular transmission of acquired characters. The 

 author's own position may be gathered from the fol- 

 lowing sentences : — 



"A hereditary change in a definite direction which 

 continues to accumulate and add to itself so as to 

 build up a more and more complex machine, must 

 certainly be related to some sort of effort, but to an 

 effort of far greater depth than the individual effort, 

 far more independent of circumstances, an effort com- 

 mon to most representatives of the same species, 

 inherent in the germs they bear rather than in their 

 substance alone, an effort thereby assured of being 

 passed on to their descendants." 



So we come to the idea of — 

 "an original impetus of life, passing from one 

 generation of germs to the following generation of 

 germs through the developed organisms which bridge 

 the interval between the generations. This impetus, 

 sustained right along the lines of evolution, among 

 which it gets divided, is the fundamental cause of 

 variations, at least of those that are regularly passeq 

 on, lli.it accumulate and create new species. In 

 general, when species have begun to diverge from a 

 common stock, they accentuate their divergence as 

 they progress in their evolution. Yet, in certain 

 definite points, they may evolve identically; in fact, 

 Ihey must do so if the hypothesis of a common 

 impetus be accepted." 



This remains too shadowy for the working 

 naturalist, but it is a fresh attempt to express what 

 must some day become clearer, the essential thought 

 of Lamarck, of Goethe, of Robert Chambers, ofJP 

 Samuel Butler, and of later vitalists — the idea of* 

 variations as intrinsic self-expressions of the organism. 



Another cardinal idea of Prof. Bergson 's book is, 

 that the evolution of life has taken a number of 

 divergent directions, leading to quite different goals. 

 It is neither a series of adaptations to accidental cir- 

 cumstances, as the mechanistic view sees it, nor the 



