SYMPATHIES AND SIMILITUDES. 127 



similitude, attraction occurs, so, by hostile dissimilitude 

 expulsion takes place. So that, for example, if vinegar 

 and water be poured around a tree, the water will be 

 absorbed and the vinegar rejected. 



Now comes the first faint suggestion of the polarity of 

 the lodestone. "So," he says, continuing his illustration, 

 u the lodestone attracts by one part by similitude and from 

 another part expels by dissimilitude." This is not the 

 mere statement that a lodestone will repel as well as at- 

 tract: nor is it, on the other hand, quite the affirmance of 

 " opposite effects at opposite ends," but it is a clear recog- 

 nition that one and the same stone will repel at one part 

 and attract at another part. Where these parts were situ- 

 ated with reference to the figure of the magnet whether 

 at its ends or otherwise Neckam did not know; but that 

 this dual property exists in it, he makes plain. Compare 

 Neckam's statement with that of Aldrovandus written four 

 centuries later; "the lodestone attracts iron by natural sym- 

 pathy at one end and repels it by antipathy at the other." 



Continuing, he explains that the appetite virtue draws 

 by friendly similitude, and the expulsive virtue rejects by 

 hostile dissimilitude; but the attracting thing again he 

 goes back to the Arabs must act more violently than the 

 attracted thing, for if equal they would counterbalance. 

 Whence it is that the lodestone draws iron and not an- 

 other lodestone, although it may have thereto greater 

 similitude, because the lodestone opposes to the lodestone 

 an equal and mutual contradiction. The iron yields itself 

 because of weaker virtue. 



The entanglement of his mind in the snares of sympa- 

 thies and similitudes is obvious. On the theory of simili- 

 tude, a lodestone should attract another lodestone ; but 

 that, he holds, is not the fact. Similia similibus cannot 

 be at fault; that would be to dispute the hypothesis, which 

 is indisputable. Wherefore, query, how can an incontro- 

 vertible fact be reconciled with an indisputable theory 

 when they diametrically disagree? 



