August 12, 1920] 



NATURE 



735 



When we ask whether the conditions which 

 have been the essential factors in human evolution 

 and progress are still in operation and likely to 

 operate for an indefinite period in the same direc- 

 tion, there is, it seems, in spite of the view as to 

 their permanence held both by Spencer and by 

 Darwin, room for doubt and for re-examination 

 of the situation. 



The struggle for existence, the natural selec- 

 tion thereby of favoured variations, and their 

 transmission by physical heredity from parent to 

 offspring, suffice to explain the evolution of man's 

 bodily structure from that of preceding ape-like 

 animals, and even to account for the development 

 of man's brain to greatly increased size and effi- 

 ciency. But a startling and most definite fact in 

 this connection has to be considered and its sig- 

 nificance appreciated. The fact to which I refer 

 is that since prehistoric man, some hundred thou- 

 sand years ago, attained the bodily structure which 

 man to-day possesses, there has been no further 

 development of that structure — measurable and of 

 such quality as separates the animals nearest to 

 man from one another. Yet man has shown enor- 

 mous " progress " since that remote epoch. The 

 brain and the mental faculties connected with it 

 have become the dominant and only progressive, 

 "evolving," attribute of man. And even in regard 

 to the brain there is, since the inception of the 

 new phase of development which we have now 

 to consider, no increase of size, though were we 

 able to compare the ultimate microscopic struc- 

 ture of the brains of earlier and later man we 

 should almost certainly find an increased com- 

 plexity in the minute structure of the later brain. 



It seems to be the fact that — when once man 

 had acquired and developed the power of com- 

 municating and receiving thought, by speech with 

 his fellow-man (so as to establish, as it were, 

 mental co-operation), and yet further of recording 

 all human thought for the common use of both 

 present and future generations, by drawing and 

 writing (to be followed by printing) — a totally new 

 factor in human evolution came into operation 

 of such overwhelming power and efficiency as to 

 supersede entirely the action of natural selection 

 of favoured bodily variations of structure in the 

 struggle for existence. Language provided the 

 mechanism of thought. Recorded language — pre- 

 served and handed on from generation to genera- 

 tion as a thing external to man's body — became 

 an ever-increasing gigantic heritage, independent 

 ■of the mechanism of variation and of the survival 

 NO. 2650, VOL. 105] 



of favoured variations which had hitherto deter- 

 mined, the organic evolution of man as of his an- 

 cestry. The observation, thought, and tradition of 

 humanity, thus independently accumulated, con- 

 tinually revised, and extended, have given to later 

 men that directing impulse which we call the 

 moral sense, that still, small voice of conscience, 

 the voice of his father-men, as well as that know- 

 ledge and skill which we call science and art. 

 These things are, and have been, of far greater 

 service to man in his struggles with the destruc- 

 tive forces of Nature and with competitors of his 

 own race than has been his strength of limb 

 and jaw. Yet they are not " inborn " in man. 

 The young of mankind enter upon the world with 

 a mind which is a blank sheet of " educable " 

 quality, upon which, by the care of his elders or 

 by the direction of his own effort, more or less of 

 the long results of time embodied in the Great 

 Record, the chief heritage of humanity, may be 

 inscribed. From this point of view it becomes 

 clear that knowledge of "that which is," and 

 primarily, knowledge of the Great Record, must 

 be the most important factor in the future " Pro- 

 gress of Mankind." Thus one of the greatest 

 services which man can render to his fellows is to 

 add to the common heritage by making new 

 knowledge of "that which is," whilst a no less 

 important task is that of sifting truth from error, of 

 establishing an unfailing devotion to veracity, and 

 of promoting the prosperity of present and future 

 generations of his race by facilitating, so far as 

 lies within human power, the assimilation by all 

 men of the chief treasures of human experience 

 and thought. 



The laws of this later "progress" are not, it 

 would seem, those of man's earlier evolution. 

 What they are, how this new progress is to be 

 made more general and its continuance assured, 

 what are the obstacles to it and how they are to 

 be removed, are matters which have not yet been 

 adequately studied. The infant science of psycho- 

 logy must eventually help us to a better under- 

 standing. Not only the reasoning intelligence, 

 but also the driving power of emotion must be 

 given due consideration. " Education " not only 

 of the youth, but also of the babe and of the 

 adult, must become the all-commanding interest 

 of the community. Progress will cease, to a 

 large extent, to be a blind outcome of natural 

 selection ; it will acquire new characteristics as 

 the conscious purpose of rational man. 



E. Ray Lankester, 



