September 19, 1901] 



NA TURE 



499 



it may be said that the realm of science is now at peace with all 

 foreign parts of the world and in a state of the happiest domestic 

 prosperity. 



But times have not been always thus pleasant and promising 

 for science. As we look backward over the history of scientific 

 progress it is seen that our realm has been taxed often to the 

 utmost in defence of its autonomj', and that the present state of 

 domestic felicity, bordering on tranquillity, has been preceded 

 often by states of domestic discord bordering on dissolution. 

 And, as we look forward into the new centurj' before us, we 

 may well inquire whether science has vanquished its foreign 

 enemies and settled its domestic disputes for good and all, or 

 whether future conquests can be made only by a similarly waste- 

 ful outlay of energy to that which has accompanied the advances 

 of the past. Especially may we fitly inquire on an occasion like 

 the present what are the types of mind and the methods of 

 procedure which make for the progress, and what are the types 

 of mind and the methods of procedure which make for the 

 regress, of science. And I venture to think that we may incjuire 

 also with profit, in some prominent instances, under what cir- 

 cumstances in the past science has waxed or waned, as the case 

 may be, in its slow rise from the myths and mysticism of earlier 

 eras to the law and order of the present day. For it is a maxim 

 of common parlance, too well jusiified, alas ! by experience, 

 that history repeats itself; or, to state the fact less gently, that 

 the blunders and errors of one age are repeated with little 

 variation in the succeeding age. This maxim is strikingly illus- 

 trated by the history of science, and it has been especially 

 deeply impressed upon us — burnt in, one might say — by the 

 scientific events of our own times. Have we not learned, how- 

 ever, some lasting lessons in the hard school of experience, and 

 may we not transmit to our successors along with the established 

 facts and principles of science the almost equally well estab- 

 lished ways and means for the advancement of science ? Will 

 it be possible for society to repeat in the twentieth century the 

 appalling intellectual blunders of the nineteenth century, or have 

 we entered on a new era in which, whatever other obstacles are 

 pending, we may expect man to stand notably less in his own 

 light as regards science than ever before ? To a consideration 

 of these and allied questions I beg your indulgence, even though 

 I may pass over ground well known to most of you, and 

 encroach, perhaps, here and there, on prominences in fields 

 controversial ; for it is only by discussion and rediscussion of 

 such questions that we come at last, even among ourselves in 

 scientific societies, to the unity of opinion and the unity of 

 purpose which lead from ideas lo their fruitful applications. 



From the earliest historic times certainly, if not from the 

 dawn of primitive humanity, down to the present day, the 

 problem of the universe has been the most attractive and the 

 most illusive subject of the attention of thinking men. All 

 systems of philosophy, religion and science are alike in having 

 the solution of this problem for their ultimate object. Many 

 such systems and sub-systems have arisen, flourished and 

 vanished, only to be succeeded by others in the seemingly 

 Sisyphean task. Gradually, however, in the lapse of ages there 

 have accumulated some elements of knowledge which give 

 inklings of partial solutions ; though it would appear that the 

 best current opinion of philosophy, religion and science would 

 again agree in the conclusion that we are yet immeasurably 

 distant from a complete solution. Almost equally attractive and 

 interesting, and far more instructive, as it appears to me, in our 

 own time is the contemplation of the ways in which man has 

 attacked this perennial riddle. It is, indeed, coming to be more 

 and more important for science to know how primitive, barba- 

 rous, and civilised man has visualised the conditions of, and 

 reached his conclusions with respect to, this problem of the 

 centuries ; for it is only by means of a lively knowledge of the 

 baseless hypotheses and the fruitless methods of our predecessors 

 that we can hope to prevent history from repeating itself 

 unfavourably. 



Looking back over the interval of two to three thousand 

 years that connects us by more or less authentic records with 

 our distinguished ancestors, we are at once struck by the ad- 

 mirable confidence they had acquired in their ability to solve 

 this grand problem. Not less admirable, also, for their ingenuity 

 and for the earnestness with which they were advanced, are the 

 hypotheses and the arguments by which men satisfied themselves 

 of the security of their tenets and theories. Roughly speaking, 

 it would appear that the science of the universe received its 

 initial impulse from earliest man in the hypothesis that the world 



NO. 1664, VOL. 64] 



is composed of two parts, the first and most important part 

 being, in fact, if not always so held ostensibly, himself, and the 

 other part being the aggregate of whatever else was left over. 

 Though dimly perceived and of little account in its effects, this 

 is, apparently, the working hypothesis of many men in the 

 civilised society of to-day. But the magnitude of the latter 

 part and its inexorable relations to man seem to have led him 

 speedily to the adoption of a second hypothesis, namely, that 

 the latter part, or world external to himself, is also the abode 

 of sentient beings, some of a lower and som.e of a higher order 

 than man, their role tending on the whole to make his sojourn 

 on this planet tolerable and his exit from it creditable, while 

 yet wielding at times a more or less despotic influence over 

 him. 



How the details of these hypotheses have been worked out is 

 a matter of something like history for a few nationalities, and is 

 a matter absorbing the attention of anthropologists, archaeo- 

 logists, and ethnologists as it concerns races in general. With- 

 out going far afield in these profoundly interesting and instruc- 

 tive details, it may suffice for the present purposes to cite two 

 facts which seem to furnish the key to a substantially correct 

 interpretation of subsequent developments. 



The first of these is that the early dualistic and antithetical 

 visualisation of the problem in question has persisted with 

 wonderful tenacity down to the present day. The accessible 

 and familiar was set over against the inaccessible and unfamiliar ; 

 or, what we now call the natural, though intimately related to, 

 was more or less opposed to the supernatural, the latter being, 

 in fact, under the uncertain sway of, and the former subject to 

 the arbitrary jurisdiction of, good and evil spirits. 



The second fact is that man thus early devised for the investi- 

 gation of this problem three distinct methods, which have like- 

 wise persisted with equal tenacity, though with varying fortunes, 

 down to the present day. The first of these is what is known as 

 the a prion method. It reasons from subjective postulates to 

 objective results. It requires, in its purity, neither observation 

 nor experiment on the external world. It often goes so far, 

 indeed, as to adopt conclusions and leave the assignment of the 

 reasons for them to a subsequent study. The second is known 

 as the historico-critical method. It depends, in its purity, on 

 tradition, history, direct human testimony and verbal congruity. 

 It does not require an appeal to Nature except as manifested in 

 man. It limits observation and experiment to human affairs. 

 The third is the method of science. It begins, in its elements, 

 with observation and experiment. Its earlier applications were 

 limited mostly to material things. In its subsequent expansion 

 it has gained a footing in nearly every field of thought. Its 

 prime characteristic is the insistence on objective verification 

 of its results. 



All of these methods have been used more or less by all 

 thinking men. But for the purposes of ready classification it 

 may be said that the first has been used chiefly by dogmatists, 

 including especially the founders and advocates of all fixed 

 creeds from the atheistic and pantheistic to the theistic and 

 humanistic : the second has been used chiefly by humanists, 

 including historians, publicists, jurists and men of letters ; and 

 the third has been used chiefly by men of science, including 

 astronomers, mathematicians, physicists, naturalists and, more 

 recently, the group of investigators falling under the compre- 

 hensive head of anthropologists. The first and the third 

 methods are frequently found to be mutually antithetical, if not 

 mutually exclusive. The second occupies middle ground. 

 Together they are here set down in the order of their apparent 

 early development and in the order of their popularly esteemed 

 importance during all historic time previous to, if not including, 

 this first year of the twentieth century. 



No summary view of the progress of science, it seems to me, 

 can be made intelligible except by a clear realisation of these 

 two facts, which may be briefly referred to as man's conception 

 of the universe and his means of investigating it. What, then, 

 in the light of these facts, has been the sequel ? The full answer 

 to this question is an old and a long story, now a matter of 

 minute and exhaustive history as regards the past twenty 

 centuries. I have no desire to recall the dramatic events 

 involved in the rise of science from the Alexandrian epoch to 

 the present day. All these events are trite enough to men of 

 science. .V mere reference to them is a sufficient suggestion of 

 the existence of a family skeleton. But, setting aside the human 

 element as much as possible, it may not be out of place or time 

 to state what general conclusions appear to stand out clearly in 



