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titudinous operations into such definite formulas as will satisfy our 

 love of plan and symmetry. "We are not content till we can sys- 

 tematize and digest, whence our continual recourse to loose analo- 

 gies and fanciful resemblances. We start from an imagined neces- 

 sity of order, or from some conception of things attractive because 

 of its apparent simplicity, and then reason out from this into the 

 facts of Nature. Mill furnishes some telling examples. " As late 

 as the Copernican controversy it was urged, as an argument in favor 

 of the true theory of the solar system, that it placed the fire, the 

 noblest element, in the center of the universe. This was a rem- 

 nant of the notion that the order of the universe must be perfect, 

 and that perfection consisted in conformity to rules of procedure, 

 either real or conventional. Again, reverting to numbers, certain 

 numbers were perfect, therefore these numbers must obtain in the 

 great phenomena of Nature. Six was a perfect number that is, 

 equal to the sum of all its factors an additional reason why there 

 must be exactly six planets. The Pythagoreans, on the other hand, 

 attributed perfection to the number ten, but agreed in thinking that 

 the perfect numbers must be somehow realized in the heavens; and 

 knowing only of nine heavenly bodies to make up the enumeration, 

 they asserted ' that there was an antichthon, or counter-earth, on 

 the other side of the sun, invisible to us.' Even Huygens was per- 

 suaded that when the number of heavenly bodies had reached twelve 

 it could not admit of any further increase. Creative power could 

 not go beyond that sacred number." * Do these concrete illustra- 

 tions of perverse reasoning strike us as ludicrous? It is because 

 they are taken from an order of ideas long since outgrown. The 

 tendencies they exemplify have not been outgrown. We have only 

 to keep a vigilant eye on our own mental conduct to be convinced 

 that we are very apt to begin with some general notion of " the fit- 

 ness of things," or what " ought to be," and to argue thence to con- 

 clusions not a whit less absurd essentially than those just referred to. 

 While these universal mental habits are conspicuous enough in 

 the higher regions of thought and begin to play tricks with us the 

 moment we undertake on our own accounts any serious speculation, 

 there are other Idols of the Tribe whose influence is perhaps more 

 commonly fatal. We all jump at conclusions, the mind feigning and 

 supposing " all other things to be somehow, though it can not see 

 how, similar to those few things by which it is surrounded " ; we all 

 allow ourselves to be unduly " moved by those things most which 

 strike and enter the mind simultaneously and suddenly, and so fill 

 the imagination." Hasty judgments are thus daily and hourly 

 passed on men and things, and rash generalizations permitted to 



* Logic, ninth edition, Book V, chapter v, 6. 



