CORRESPONDENCE, 1856-66. 305 



in one volume. For B. is the man of all others, according to my 1861 

 experience, who is referred to by citation of one work for what 

 is in another. How could aught else happen to a cove who 

 called one of his writings Lectiones Mathematicce, and another 

 Lectiones Geometricce, and then treated what is considered as 

 exclusively Geometrical (as Euclid V. wrongly is) in his Mathe- 

 matical lectures, pp. 8, 9 (i.e. one word shared between them) ? 

 For metaphysical read psychological. I don't object to the word 

 a few lines higher up. 



Do you know the use of the word metaphysical, which is 

 growing up among the writers of the examination books which 

 have taken the place of all others ? I mean at Cambridge. It 

 means requiring thought, and proceeding without symbolic calcu- 

 lation. When a proof of two pages of symbol drumming is 

 avoided by an act of reasoning, it is said to be ' too metaphysical.' 

 This is one of the consequences of the death and burial of 

 psychological thought in Cambridge. There seems to be a com- 

 plete acquiescence in the maxim that Oxford shall settle what 

 the world shall think, and Cambridge shall settle who is to be 

 Senior Wrangler. It is getting worse and worse from day to 

 day. Are any of the younger men alive to the facts ? With 

 best remembrances to Lady Affleck, 



I am yours very truly, 



A. DE MORGAN. 



To Rev. Dr. Wliewell. 

 41 Chalcot Villas, Adelaide Road, Jan. 20, 1861. 



MY DEAR SIR, There are some mistakes which are too small 

 to be of any consequence, and some which are too large. Ex- 

 tremes meet; oo is curiously a comrade of +00. . . .* 



The reason I call $ 3 2* 5=0 a celebrated equation is 

 because it was the one on which Wallis chanced to exhibit 

 Newton's method when he first published it; in consequence 

 of which every numerical solver has felt bound in duty to make 

 it one of his examples. Invent a numerical method, neglect to 

 show how it works on this equation, and you are a pilgrim who 

 does not come in at the little wicket (vide J. Bunyan). 



Newton was anything but illiterate. He knew Bacon. His 

 silence is most marked. How could he avoid every possible 



1 Referring, I think, to some error in a figure in a former letter. 

 S. E. DE M. 



X 



