370 FALLACIES. 



movable which moves all other things, is the old scholastic 

 error of a primum mobile. 



The following instance I quote from Archbishop Whately's 

 Rhetoric : " It would be admitted that a great and permanent 

 diminution in the quantity of some useful commodity, such as 

 corn, or coal, or iron, throughout the world, would be a serious 

 and lasting loss ; and again, that if the fields and coal mines 

 yielded regularly double quantities, with the same labour, we 

 should be so much the richer ; hence it might be inferred, that 

 if the quantity of gold and silver in the world were diminished 

 one -half, or were doubled, like results would follow; the 

 utility of these metals, for the purposes of coin, being very 

 great. Now there are many points of resemblance and many 

 of difference, between the precious metals on the one hand, 

 and corn, coal, &c., on the other ; but the important circum- 

 stance to the supposed argument is, that the utility of gold and 

 silver (as coin, which is far the chief) depends on their value, 

 which is regulated by their scarcity ; or rather, to speak strictly, 

 by the difficulty of obtaining them ; whereas, if corn and coal 

 were ten times as abundant (i.e. more easily obtained), a bushel 

 of either would still be as useful as now. But if it were twice 

 as easy to procure gold as it is, a sovereign would be twice 

 as large ; if only half as easy it would be of the size of a 

 half-sovereign, and this (besides the trifling circumstance of 

 the cheapness or dearness of gold ornaments) would be all the 

 difference. The analogy, therefore, fails in the point essential 

 to the argument." 



The same author notices, after Bishop Copleston, the case 

 of False Analogy which consists in inferring from the simi- 

 larity in many respects between the metropolis of a country 

 and the heart of the animal body, that the increased size of 

 the metropolis is a disease. 



Some of the false analogies on which systems of physics 

 were confidently grounded in the time of the Greek philoso- 

 phers, are such as we now call fanciful, not that the resem- 

 blances are not often real, but that it is long since any one has 

 been inclined to draw from them the inferences which were 

 then drawn. Such, for instance, are the curious speculations 



