February 6, 1902] 



NA TURE 



329 



speak of the private memory as the personal past, as the next 

 wider area of knowledge as the traditional or historical past, 

 then one might call all that great and inspiring background of 

 remoter geological time, the inductive past. 



And this great discovery of the inductive past was got by the 

 discussion and rediscussion and effective criticism of a number 

 of existing facts, odd-shaped lumps of stone, streaks and band- 

 ings in quarries and cliffs, anatomical and developmental details 

 that had always been about in the world, that had been lying at 

 the feet of mankind so long as mankind had existed, but that 

 no one had ever dreamt before could supply any information at 

 all, much more reveal such astounding and enlightening vistas. 

 Looked at in a new way they became sources of dazzling and 

 penetrating light; the remoter past lit up and became a picture. 

 Considered as effects, compared and criticised, they yielded a 

 clairvoyant vision of the history of interminable years. 



And now — if it has been possible for men by picking out a 

 number of suggestive and significant looking things in the 

 present, by comparing them, criticising them, and discussing 

 them, with a perpetual insistence upon why'* without any guid- 

 ing tradition, and indeed in the teeth of established beliefs, to 

 construct this amazing searchlight of inference into the remoter 

 past — is it really, after all, such an extravagant and hopeless 

 thing to suggest that, by seeking for operating causes instead of 

 for fossils and by criticising them as persistently and thoroughly 

 as the geological record has been criticised, it may be possible 

 to throw a searchlight of inference forward instead of backward 

 and to attain to a knowledge of coming things as clear, as 

 universally convincing and infinitely more important to man- 

 kind than the clear vision of the past that geology has opened 

 to us during the nineteenth century ? 



Let us grant that anything to correspond with the memory, 

 anything having the same relation to the future that memory 

 has to the past, is out of the question. We cannot imagine, 

 of course, that we can ever know any personal future to cor- 

 respond with our personal past, or any traditional future to 

 correspond with our traditional past. But the possibility of 

 an inductive future to correspond with that great inductive 

 past of geology and archaeology is an altogether different 

 thing. 



I must confess that I believe quite firmly that an inductive 

 knowledge of a great number of things in the future is be- 

 coming a human possibility. I believe that the time is drawing 

 near when it will be possible to suggest a systematic explora- 

 tion of the future. And you must not judge the practicability 

 of this enterprise by the failures of the past. So far nothing 

 has been attempted, so far no first-class mind has ever focussed 

 itself upon these issues. But suppose the laws of social and 

 political development, for example, were given as many brains, 

 were given as much attention, criticism and discussion as we 

 have given to the laws of chemical combination during the last 

 fifty years — what might we not expect ? 



To the popular mind of to-day there is something very diffi- 

 cult in such a suggestion, soberly made. But here, in this 

 Institution which has watched for a whole century over the 

 splendid adolescence of science, and where the spirit of science 

 is surely understood, you will know that as a matter of fact 

 prophecy has always been inseparably associated with the idea 

 of scientific research. The popular idea of scientific investiga- 

 tion is a vehement, aimless collection of little facts, collected as 

 the bower bird collects shells and pebbles, in methodical little 

 rows, and out of this process, in some manner unknown to the 

 popular mind, certain conjuring tricks — the celebrated wonders 

 of science — in a sort of accidental way emerge. The popular 

 conception of all discovery is accident. But you will know that 

 the essential thing in the scientific process is not the collection 

 of facts, but the analysis of facts ; facts are the raw material and 

 not the substance of science ; it is analysis that has given us all 

 ordered knowledge, and you know that the aim and the test and 

 the justification of the scientific process is not a marketable 

 conjuring trick, but prophecy. Until a scientific theory yields 

 confident forecasts you know it is unsound and tentative ; it is 

 mere theorising, as evanescent as art talk or the phantoms 

 politicians talk about. The splendid body of gravitational 

 astronomy, for example, establishes itself upon the certain fore- 

 cast of stellar movements, and you would absolutely refuse to 

 believe its amazing assertions if it were not for these same 

 unerring forecasts. The whole body of medical science aims, 

 and claims the ability, to diagnose. Meteorology constantly 

 and persistently aims at prophecy, and it will never stand in a 



NO. 1684, VOL. 65] 



place of honour until it can certainly foretell. The chemist 

 forecasts elements before he meets them — it is very properly his 

 boast — and the splendid manner in which the mind of Clerk 

 Maxwell reached in front of all experiment and foretold those 

 things that Marconi has materialised is familiar to us all. 



And if I am right in saying that science aims at prophecy, 

 and if the specialist in each science is in fact doing his best nozo 

 to prophesy within the limits of his field, what is there to stand 

 in the way of our building up this growing body of forecast into 

 an ordered picture of the future that will be just as certain, just 

 as strictly science, and perhaps just as detailed as the picture 

 that has been built up within the last hundred years to make the 

 geological past ? Well, so far and until we bring the prophecy 

 down to the affairs of man and his children, it is just as possible 

 to carry induction forward as back ; it is just as simple and sure 

 to work out the changing orbit of the earth in the future until 

 the tidal drag hauls one unchanging face at last towards the 

 sun as it is to work back to its blazing and molten past. Until 

 man comes in, the inductive future is as real and convincing as 

 the inductive past. But inorganic forces are the smaller part 

 and the minor interest in this concern. Directly man becomes 

 a factor the nature of the problem changes, and our whole 

 present interest centres on the question whether man is, indeed, 

 individually and collectively incalculable, a new element which 

 entirely alters the nature of our inquiry and stamps it at once 

 as vain and hopeless, "Or whether his presence complicates, 

 but does not alter, the essential nature of the induction. How 

 far may we hope to get trustworthy inductions about the future 

 of man ? 



Well, I think, on the whole, we are inclined to underrate our 

 chance of certainties in the future just as I think we are inclined 

 to be too credulous about the historical past. The vividness of 

 our personal memories, which are the very essence of reality to 

 us, throws a glamour of conviction over tradition and past 

 inductions. But the personal future must in the very nature of 

 things be hidden from us so long as time endures, and this black 

 ignorance at our very feet, this black shadow that corresponds to 

 the brightness of our memories behind us, throws a glamour of 

 uncertainty and unreality over all the future. We are continually 

 surprising ourselves by our own will or want of will ; the 

 individualities about us are continually producing the unexpected, 

 and it is very natural to reason that as we can never be precisely 

 sure before the time comes what we are going to do and feel, 

 and if we can never count with absolute certainty upon the acts 

 and happenings even of our most intimate friends, how much 

 the more impossible is it to anticipate the behaviour in any 

 direction of states and communities ? 



In reply to which I would advance the suggestion that an 

 increase in the number of human beings considered may 

 positively simplify the case instead of complicating it, that as 

 the individuals increase in number they begin to average out. 

 Let me illustrate this point by a comparison. Angular pit sand 

 has grains of the most varied shapes. Examined microscopically 

 you will find all sorts of angles and outlines and variations. 

 Before you look, you can say of no particular grain what its 

 outline will be. And if you shoot a load of such sand from a 

 cart you cannot foretell with any certainty where any particular 

 grain will be in the heap that you make. But you can tell, you 

 can tell pretty definitely, the form of the heap as a whole. And 

 further, if you pass that sand through a series of shoots, and 

 finally drop it some distance to the ground, you will be able to 

 foretell that grains of a certain sort of form and size will for the 

 most part be found in one part of the heap, and grains of 

 another sort of form and size will be found in another part of the 

 heap. In such a case, you see, the thing as a whole may be 

 simpler than its component parts, and this I submit is also the 

 case in many human affairs. So that because the individual 

 future eludes us completely, that is no reason why we should 

 not aspire to, and discover and use, safe and serviceable general- 

 isations upon countless important issues in the human destiny. 



But there is a very grave and important-looking difference 

 between a load of sand and a multitude of human beings, and 

 this I must face and examine. Our thoughts and wills and 

 emotions are contagious. An exceptional sort of sand grain, 

 a sand grain that was exceptionally big and heavy, for example, 

 exerts no influence worth considering upon any other of the sand 

 grains in the load. They will fall and roll and heap themselves 

 just the same, whether that exceptional grain is with them or 

 not. But an exceptional man comes into the world, a Cssar or 

 a Napoleon or a Peter the Hermit, and he appears to persuade 



