394 TH INTELLECTUAL RISE IN ELECTRICITY. 



for if the earth has the power of attracting those things 

 which are agreeable to it, it will likewise have the power 

 of repelling those things which injure it and do not please 

 it;" and specifically, if one planet "impresses its contrary 

 influence upon another, that other resists the same by its 

 own repelling virtue." For a modern philosopher and a 

 skillful experimentalist, this notion of an expulsive virtue 

 or repelling force actually existing in the earth was a new 

 one. Clearly, moreover, he is not evolving that supposi- 

 tion out of his inner consciousness, but because he has 

 some tangible physical reason for it. Observe first, that 

 he has imputed to the earth not one, but many different 

 virtues; second, that he has denied that it is by substance 

 a magnet; and, third, that he gives it this new repelling 

 effect. Now why is he doing this? 



Let me recall here a peculiarity in mode of reasoning 

 common to all of these old philosophers save perhaps 

 Gilbert and that is, they always present their theory first, 

 and then detail some physical phenomena, usually new 

 ones, which they think sustain it the idea being to lead 

 the student to suppose that the working of the superior 

 brain alone has produced the conception, the truth of 

 which detected nature is afterwards compelled to admit. 

 This is not only putting the cart before the horse, but also 

 causing it to appear that the vehicle tows the animal. 

 In that way Descartes puts his spiral-ribbon theory first, 

 and his observation of the iron filings in the magnetic 

 spectrum last; Cabaeus his rebounding-effluvia hypothesis 

 before the repelled-chaff experiment. 



Von Guericke is evidently following the same course; or 

 in other words, he has found some strange and novel 

 effects, and all this new theory about the virtues, etc., 

 rests on that basis; while, like his predecessors, he fails to 

 perceive that the credit and the honor due to him who is 

 gifted with eyes to see and ears to hear what the laws of 

 nature are revealing cannot be enhanced by an effort to 

 make the world believe that the true source of it all is not 

 nature, but himself. 



