Auo;. 15, 1872] 



NATURE 



307 



century for a reider, as God has waited six thousand yearj for an 

 observer. " 



And when a yet greater than Kepler was bringing to its final 

 issue that grandest of all Scientific Conceptions, long pandered 

 over by his almost siiperhiimin intellect — which linked together 

 the Heavens and the Earth, the Planets and the Sun, the Pri- 

 maries and their Satellites, and included even the vagrant 

 Comets, in the nexus of a Universal Attraction — establishing for 

 all time the truth for whose utterance Galileo had been con- 

 demned, and giving to Kepler's Laws a significance of which 

 their author had never dreamed — what was the meaning of that 

 agitation which prevented the Plulosopher from completing his 

 computation, and compelled him to hand it over to his friend ? 

 Tiiat it was not tlie thought of his own greatness, but the glimpse 

 of the grand Universal Order thus revealed to his mental vision, 

 which shook the serene and massive soul of Newton to its foun- 

 dat'ons, we have the proof in that beautiful comparison in which 

 he likened himself to a Child picking up shells on the shore of 

 the vast Ocean of Truth — a comparison which will be evidence 

 to all time at once of his true Philosophy with his profound 

 Humility. 



Though it is with the Intellectual Representation of Nature 

 which we call SlUhcc^ that we are primarily concerned, it will 

 not be without its use to cast a glance in the first instance at the 

 other two principal characters under which Man acts as her In- 

 terpreter — those, namely, of the Artist and of the Poet. 



The Artist serves as the Interpeter of Nature, net when he 

 works as the mere copyist, delineating that which he sees with 

 bis bodily eyes, and which we could see as well as ourselves ; but 

 when he endeavours to awaken within us the perception of those 

 beauties and harmonies which his own trained sense has recog- 

 nised, and thus impart to us the pleasure he has himself derived 

 from their contemplation. As no two Artists agree in the original 

 constitutions and acquired habits of their Minds, all look at 

 Nature with ditTerent (mental) eyes ; so that to each, Nature is 

 what /w individually sees in Jut, 



The Poet, again, serves as the Interpreter of Nature, not so 

 much when by skilful word-painting (whether in prose or verse) 

 he calls up before our mental vision the picture of some actual 

 or ideal scene, however beautiful ; as when, by rendering into 

 appropriate forms those deeper impressions made by the Nature 

 around him on the Moral and Emotional part of his own Nature, 

 he transfers these impressions to the corresponding part of 

 ours. For it is the attribute of the true Poet to penetrate the 

 secret of those mysterious inlluences which we all unknowingly 

 experience ; and having discovered this to himself, to bring 

 others, by the power he thus wields, into the like sympathetic 

 relation with Nature — evoking with skilful touch the varied 

 response of the Soul's finest chords, heightening its joys, assuag- 

 ing iis griefs, and elevating its aspirations. Whilst, then, the 

 Artist aims to picture what he sees in Nature, it is the object of 

 the Poet to represent what he feels in Nature ; and to each true 

 Poet, Xature is wliat iie individually finds in her. 



The Philosopher's interpretation of Nature seems less indi- 

 vidual than that of the Artist or the Poet, because it is based 

 on facts which any one may verify, and is elaborated by reason- 

 ing processes of which all admit the validity. He looks at the 

 Universe as a vast Book lying open before him, of which he has 

 in the first place to learn the characters, then to master the lan- 

 guage, and finally to apprehend the ideas which that language 

 conveys. In that Book there are many Chapters, treating of dif- 

 ferent subjects ; and as Life is too short for any one man to 

 grasp the whole, the Scientific interpretation of this Book comes 

 to be the work of many Intellects, differing not merely in the 

 range but also in the character of their powers. But whilst there 

 are "diversities of gifts," there is "the same spirit." While 

 each takes his special direction, the general Method of study is 

 the same for all. And it is a testimony alike to the truth of that 

 Method and to the Unity of Nature, that there is an ever-in- 

 creasing tendency towards agreement among those wlio use it 

 aright — temporary differences of interpretation being removed, 

 sometimes by a more complete mastery of her language, some- 

 times by a better apprehension of her ideas — and lines of pur- 

 suit which had seemed entirely distinct or even widely divergent, 

 being found to lead at last to one common goal. And it is this 

 agreement which gives rise to the general belief — in many, to 

 the confident assurance — that the Scientific interpretation of 

 Nature represents her not merely as she seems, but as she 

 really is. 



When, however, we carefully examine the foundation of that 



assurance, we find reason to distrust its security ; for it can be 

 shown to be no less true of the Scientific conception of Na'ure, 

 than it is of the Artistic or the Poetic, that it is a representation 

 fram:d by the Mind itself out of the materials supplied by the 

 impressions which external objects make upon the Senses ; so 

 that to each Man of Science, Nature is what he individually be- 

 lieves Iter to be. And that belief will rest on very different bases, 

 and will have very unequal values, in different departments of 

 Science. Thus, in what are commonly known as the "exact" 

 Sciences, of which Astronomy may be taken as the type, the 

 data afforded by precise methods of observation can be made the 

 basis of reasoning, in every step of which the Mathematician 

 feels the fullest assurance of certainty ; and the final deduction is 

 justified either by its conformity to knoivn or ascertainable facts 

 — as when Kepler determined the elliptic orbit of Mars ; or by 

 the fulfilment of the predictions it has sanctioned — as in the oc- 

 currence of an Eclipse or an Occultation at the precise moment 

 specified many years previously ; or, still more emphatically, by 

 the actual discovery of phenomena till then unrecognised — as 

 when the Perturbations of the planets, shown by Newton to be 

 the necessary results of their mutual attraction, were proved by 

 observation to have a real existence ; or as when the unknown 

 disturber of Uranus was found in the place assigned to him by 

 the computations of Adams and Le Verrier. 



We are accustomed, and I think most riglttly, to speak of 

 these achievements as triumphs of the Human Intellect. But 

 the very phase implies that the work is done by Mental Agency ; 

 and the coincidence of its resulLs with the facts of observation is 

 far from proving the Intellectual process to have been correct. 

 For we learn from the honest confession of Kepler, that he was 

 led to the discovery of the Elliptic orbit of Mars by a series of 

 happy accidents, which turned his erroneous guesses into the 

 right direction ; and to that oF the passage of the Radius 

 Vector over equal areas in equal times, by the notion of a 

 whirling force emanating from the Sun, which we now regard 

 as an entirely wrong conception of the cause of orbital revolu- 

 tion. * It should always be remembered, moreover, that the 

 Ptolemaic system of Astronomy, with all its cumbrous ideal 

 mechanism of "Centric and Excentric, Cycle and Epicycle, 

 Orb in Orb," did intellectually represent all that the Astronomer, 

 prior to the invention of the Telescope, could see from his actual 

 standpoint, the Earth, with an accuracy which was proved by 

 the fulfilment of his anticipations. And in that last and most 

 memorable prediction which has given an imperishable fame to 

 our two illustrious contemporaries, the inade'^uacy of the basis 

 afforded by actual observation of the perturbations of Uranus 

 required that it should be supplemented by an assumption of the 

 probable distance of the disturbing Planet beyond, which has 

 been shown by subsequent observation to have been only an 

 approximation to the truth. 



Even in this most exact of Sciences, therefore, we cannot pro- 

 ceed a step without translating the actual Phenomena of Nature 

 into Intellectual Representations of those phenomena ; and it is 

 because the Newtonian conception is not only the most simple, 

 but is also, up to the extent of our present knowledge, universal 

 in its conformity to the facts of observation, that we accept it 

 as the only Scheme of the Universe yet promulgated, which 

 satisfies our Intellectual requirements. 



When, under the reign of the Ptolemaic System, any new in- 

 equality was discovered in the motion of a Planet, a new wheel 

 had to be added to the ideal Mechanism— as Ptolemy said, "to 

 save appearances." If it should prove, a century hence, that 

 the motion of Neptune himself is disturbed by some o her attrac- 

 tion than that exerted by the interior Planets, we should con- 

 fidently expect that not an ideal but a real cause for that disturb- 

 ance will be found in the existence of another Planet beyond. 

 But I trust that I have now made it evident to you, that this 

 confident expectation is not justified by any absolute ne:essity of 

 Nature, but arises entirely out of our belief in her Uniformity ; 

 and into the grounds of this and other Piimary Beliefs, which 

 serve as the foundation of all Scientific reasoning, we shall pie- 

 sently inquire. 



There is another class of cases, in which an equal certainty is 

 generally claimed for conclusions that seem to flow immediately 

 from observed facts, though really evolved by Intellectual pro- 

 cesses ; the apparent simplicity and directness of those processes 

 either earning them to be entirely overlooked, or veiling the as- 

 sumptions on which they are based. Thus Mr. Lockyer 



* See Drinkwater's "Life of Kepler," in the Library of Useful Know^ 

 ledge, pp. 26 ii. 



