224 JAMES CLERK MAXWELL. [CHAP. VIII. 



resolved to try the effect of our learning upon a mixed com- 

 pany. 



" Not to dazzle them too much at first, we merely 

 ventured to quote to an elderly lady a passage from Griffin 

 on Presbyopic Vision. She intended to get a new pair of 

 spectacles, and hoped that optical advice, fresh from College, 

 might assist her in her choice. She was surprised to learn 

 that she must ascertain the distance behind the retina at 

 which the image of a distant object is formed, and that she 

 might then determine from the proper formula the focal 

 lengths of the lenses she required. 



" Shocked at the unhesitating way in which we proposed 

 the most barbarous if not impossible operations, she replied 

 that she would rather try several pairs, and take those that 

 suited her best." 



"... When this indecision" (of opinion) " cannot be 

 traced to hypochondria, we generally find indications of a 

 defective appreciation of quantity and a deceptive memory. 



" Its victims measure reasons by their number and not 

 by their weight. They do not say ' so much/ but ' so 

 many things to be said on both sides.' To make the 

 number equal on both sides they will split an argument or 

 state it in several ways. These ingenious self- tor mentors 

 have invented a form of reasoning which ought to take its 

 place beside the ' reasoning in a circle.' We may call it 

 reasoning in a corner, or tergiversation. ... It derives its 

 name from the motion of the imprisoned monarch in a 

 drawn game at draughts, and is resorted to when pressed by 

 a disjunctive argument. ... In this way these clacking 

 metronomes endeavour to transfer their inquietude to their 

 neighbours." 



"... It is this consciousness of aim that gives to 

 their experience the character of self-education. While other 

 men are drifted hither and thither by conflicting influences, 

 their sails seem to resolve every blast in a favourable direc- 

 tion. To them catastrophes are lessons and mysteries 

 illustrations. Every thing and every person is estimated 

 by its effect in accelerating personal advancement. 



