174 THE GROWTH OF SCIENCE IN THE NINETEENTH CENTURY. 



driven far back round the full circle of natural knowledge the dark 

 clouds of the unknown which wrap us all about, but also the many 

 walk in the zone of light thus increasingly gained. If it be true that 

 the few^ to-da}' are, in respect to natui'al knowledge, far removed from 

 the few of those days, it is also true that nearly all which the few 

 alone knew then, and much which they did not know, has now become 

 the common knowledge of the many. 



What, however, I may venture to insist upon here is that the differ- 

 ence in respect to natural knowledge, whatever be the case with other 

 differences between then and now, is undoubtedl}^ a difference which 

 means progress. The span between the science of that time and the 

 science of to-day is bej^ond all question a great stride onward. 



We may say this, but we must say it without boasting. For the 

 very story of the past which tells of the triumphs of science^ l)ids the 

 man of science put awa}' from him all thoughts of vainglory, and that 

 by many tokens. 



Whoever, working at any scientific pro))lem. has occasion to study 

 the inciuiries into the same problem made by some fellow-worker in the 

 years long gone by, comes away from that study humbled by one or 

 other of two different thoughts. On the one hand, he may find, when 

 he has translated the language of the past into the phraseology of 

 to-day, how near was his forerunner of old to the conception which 

 he thought, with pride, was all his own, not onh^ so true ])ut so 

 new. On the other hand, if the ideas of the investigator of old, 

 viewed in the light of modern knowledge, are found to be so wide of 

 the mark as to seem a])sui-d. the sinil(> which begins to play upon the 

 lips of the modern is checked by the thought. Will the ideas which I 

 am now putting forth, and which I think explain so clearly, so fully, 

 the problem in hand, seem to some worker in the far future as wrong 

 and as fantastic as do these of my forerunner to me? In either case 

 his personal pride is checked. Further, there is written clearly on 

 each page of the history of science, in characters which can not be 

 overlooked, the lesson that no scientific truth is Ijorn anew, coming by 

 itself and of itself. Each new truth is always the offspring of some- 

 thing which has gone before, becoming in turn the parent of some- 

 thing coming after. In this aspect the man of science is unlike, or 

 seems to be unlike, the poet and the artist. The poet is born, not 

 made; he rises up, no man knowing his beginnings; when he goes 

 away, though men after him may sing his songs for centuries, he him- 

 self goes away wholly, having taken with him his mantle, for this he 

 can give to none other. The man of science is not thus creative; he 

 is created. His work, however great it be, is not wholly his own; it 

 is in part the outcome of the work of men who have gone before. 

 Again and again a conception which has made a name great has come 

 not so much by the man's own effort as out of the f idlness of time. 



