Nov. 25, 1880] 



NATURE 



81 



questions specially fitted for discussion here and now. I 

 may, therefore, commence by inquiring what species of 

 "mental peculiarity" my critic himself exhibited when 

 he seriously asked me whether I had proved by experiinejit 

 that a thing might have been what it is not ! ! 



The title of Mr. Spencer's pamphlet informs us that 

 it deals with Cn'ficis/iis; and I am the first of the sub- 

 jects brought up in it for vivisection, albeit I have been 

 guilty (on Mr. Spencer's own showing) only of "■ /acit!y" 

 ■expressing an opinion ! Surely my vivisector exhibits 

 here also some kind of ''mental peculiarity." Does a 

 man become a critic because he quotes, with commenda- 

 tion if you like, a clever piece of analysis or exposition 

 published by another ? 



In Nature for July 17, 1879, I reviewed Sir E. 

 Beckett's able little book, "Origin of the Laws of 

 Nature," and as an illustration of that author's method I 

 said : — 



" He follows out in fact, in his own way, the hint given 

 by a great mathematician (Kirkman) who made the follow- 

 ing exquisite translation of a well-known definition : — 



" ' Evolution is a change from an indefinite, incoherent, 

 homogeneity to a definite, coherent, heterogeneity, through 

 continuous differentiations and integrations.' 



" [Translation into plain English] — ' Evolution is a 

 change from a nohowish, untalkaboutable, all-alikeness, 

 to a somehowish and in-general-talkaboutable not-all- 

 alikeness, by continuous somethingelsifications and stick- 

 togetherations.' " 



Later in my article occurs the following paragraph, 

 which also is quoted by Mr. Spencer :— 



"When the purposely vague statements of the ma- 

 terialists and agnostics are thus stripped of the tinsel of 

 high-flown and unintelligible language, the eyes of the 

 thoughtless who have accepted them on authority (!) are 

 at last opened, and they are ready to exclaim with 

 Titania 



" Methinks ' I was enamour'd of an ass. ' " 



The translation is from Kirkman's remarkable work, 

 " Philosophy without Assumptions," which at that date I 

 had just read with pleasure and profit. Humiliating as 

 the confession may appear, I there saw Mr. Spencer's 

 "Formula" for the first time, and I did not notice the 

 title given to it. Hence, in quoting it from Kirkman, I 

 very naturally called it by its proper name, a " Defini- 

 tion." For this I have incurred the sore displeasure and 

 grave censure of the inventor of the definition. It seems 

 I should have called him the disc07'eiri- of the formula ! 

 Now this is no petty quibble on words. It involves, as 

 you will see immediately, an excessively important scien- 

 tific distinction, to which your attention cannot be too 

 early directed. 



Mr. Spencer complains that an American critic (whose 

 estimate is "tacitly" agreed in by Mr. Matthew Arnold) 

 says of the " Formula of Evolution " ; — " This may be all 

 true, but it seems at best rather the blank form for a 

 universe than anything corresponding to the actual world 

 about us." On which I remark, with Mr. Kirkman, 

 " Most just, and most merciful I " But mark what Mr. 

 Spencer says : — 



" On which the comment may be that one who had 

 studied celestial mechanics as much as the reviewer has 

 studied the general course of transformations, might simi- 

 larly have remarked that the formula— 'bodies attract 

 one another directly as their masses and inversely as the 

 squares of their distances,' was at best but a blank form 

 for solar systems and sidereal clusters." 



We now see why Mr. Spencer calls his form of words 

 a Formula, and why he is indignant at its being called a 

 Definition. He puts his Formula of Evolution along-side 

 of the Law of Gravitation ! Yet I think you will very' 

 easily see that it is a definition, and nothing more. By 

 the help of the Law of Gravitation (not very accurately 

 quoted by Mr. Spencer) astronomers are enabled to 



predict the positions of known celestial bodies four years 

 beforehand, in the Nautical Almanac, with an amount of 

 exactness practically depending merely upon the accuracy 

 of the observations which are constantly being made : — 

 and, with the same limitation, the prediction could be 

 made for 1900 a.d., or 2000 A.D., if necessary. If now 

 Mr. Spencer's form of words be a formula, in the sense 

 in which he uses the term as applied to the Law of 

 Gravitation, it ought to enable us to predict, say four 

 years before-hand, the history of Europe, with at least its 

 main political and social changes ! For I\Ir. Spencer 

 says that his "formula" expresses "all orders of changes 

 in their general course, — astronomic, geologic, biologic, 

 psychologic, sociologic " ; and therefore "could not pos- 

 sibly be framed in any other than words of the highest 

 abstractness." 



Added, November 11, 1880. 



Mr. Kirkman has lately "discovered a formula" more 

 general than that of Evolution, the " Formula of Universal 

 Change." Here it is : — 



" Change is a perichoretical synechy of pamparal- 

 lagmatic and porroteroporeumatical differentiations and 

 integrations." 



Even to this all-embracing formula, with Mr. Spencer's 

 leave, I would apply the humbler but fitter term " defini- 

 tion." 



Of Mr. Spencer's farther remarks there are but three 

 which are directed specially against myself. (Mr. Kirkman 

 is quite able to fight his own battles.) He finds evidence 

 of " idiosyncrasies " and what not, in the fact that, after 

 proclaiming that nothing could be known about the 

 physical world except by observation and experiment, I 

 yet took part in writing the "Unseen Universe"; in 

 which arguments as to the Unseen are based upon sup- 

 posed analogies with the seen. He says : — "clearly, the 

 relation between the seen and the unseen universes cannot 

 be the subject of any observation or experiment ; since, 

 by the definition of it, one term of the relation is absent." 

 I do not know exactly what " mental peculiarity " Mr. 

 Spencer exhibits in this statement. But it is a curious 

 one. Am not 1, the thinker, a part of the Unseen ; no 

 object of sense to myself or to others ; and is not that term 

 of relationship between the seen and the Unseen always 

 present .' But besides this, Mr. Spencer mistakes the 

 object of the book in question. The theory there deve- 

 veloped was not put forward as probable, its purpose was 

 attained when it was shown to be conceivable and not 

 inconsistent with any part of our present knowledge. 



Mr. Spencer's second fault-finding is apropos of a 

 Review of Thomson and Taif s Nat. Phil. (NATURE, 

 July 3, 1879) by Clerk-Maxwell. Maxwell, knowing of 

 course perfectly well that the authors were literally 

 quoting Newton, and that they had expressly said so, 

 jocularly remarked " Is it a fact that 'matter' has any 

 power, either innate or acquired, of resisting external 

 influences .' '' Mr. Spencer says :— " And to Prof. Clerk- 

 Maxwell' s question thus put, the answer of one not 

 having a like mental peculiarity with Prof. Tail, must surely 

 be — No." ;\tr. Spencer, not being aware that the passage 

 is Newton's, and not recognising Maxwell's joke, thinks 

 that Maxwell is at variance with the authors of the book ! 



Finally, Mr. Spencer attacks me for inconsistency &c. 

 in my lecture on Force (NATURE, September 21, 1876). 

 I do not know how often I may have to answer the 

 perfectly groundless charge of having, in that Lecture, 

 given two incompatible definitions of the same term. 

 At any rate, as the subject is much more important than 

 my estimates of Mr. Spencer's accuracy or than his esti- 

 mates of my "mental peculiarities," I may try to give him 

 clear ideas about it, and to show him that there is no 

 inconsistency on the side of the mathematicians, however 

 the idea of force may have been muddled by the meta- 

 physicians. For that purpose I shall avoid all reference 

 to "differentiations" and "integrations" ; either as they 



