530 FALLACIES. 



classes, must be of different natures, and have different causes. This prej- 

 udice, so evidently of the same origin with those already treated of, marks 

 more especially the earliest stage of science, when it has not yet broken 

 loose from the trammels of every -day phraseology. The extraordinary 

 prevalence of the fallacy among the Greek philosophers may be accounted 

 for by their generally knowing no other language than their own ; fi'om 

 which it was a consequence that their ideas followed the accidental or ar- 

 bitrary combinations of that language, more completely than can happen 

 among the moderns to any but illiterate persons. They had great difficulty 

 in distinguishing between things which their language confounded, or in 

 putting mentally together things which it distinguished; and could hardly 

 combine the objects in nature, into any classes but those which were made 

 for them by the popular phrases of their own country; or at least could 

 not help fancying those classes to be natural and all others arbitrary and 

 artificial. Accordingly, scientific investigation among the Greek schools 

 of speculation and their followers in the Middle Ages, was little more than 

 a mere sifting and analyzing of the notions attached to common language. 

 They thought that by determining the meaning of words, they could be- 

 come acquainted with facts. " They took for granted," says Dr. Whewell,* 

 " that philosophy must result from the relations of those notions which are 

 involved in the common use of language, and they proceeded to seek it by 

 studying such notions." In his next chapter, Dr. Whewell has so well 

 illustrated and exemplified this error, that I shall take the liberty of quot- 

 ing him at some length. 



"The propensity to seek for principles in the common usages of lan- 

 guage may be discerned at a very early period. Thus we have an example 

 of it in a saying which is reported of Thales, the founder of Greek philoso- 

 phy. When he was asked, ' What is the greatest thing ?' he replied '■Place; 

 for all other things are in the world, but the world is in it.' In Aristotle 

 we have the consummation of this mode of speculation. The usual point 

 from which he starts in his inquiries is, that xoe say thus or thus in common 

 language. Thus, when he has to discuss the question whether there be, in 

 any part of the universe, a void, or space in which there is nothing, he in- 

 quires first in how many senses we say that one thing is in another. He 

 enumerates many of these ; we say the part is in the whole, as the finger is 

 in the hand ; again we say, the species is in the genus, as man is included 

 in animal; again, the government of Greece is in the king; and various 

 other senses are described and exemplified, but of all these the most proper 

 is when we say a thing is in a vessel, and generally in place. He next ex- 

 amines whvii place is, and comes to this conclusion, that 'if about a body 

 there be another body including it, it is in place, and if not, not.' A body 

 moves Avhen it changes its place; but he adds, that if water be in a vessel, 

 the vessel being at rest, the parts of the water may still move, for they are 

 included by each other ; so that while the whole does not change its place, 

 the parts may change their place in a circular order. Proceeding then to 

 the question of a void, he as usual examines the different senses in which 

 the term is used, and adopts as the most proper, jstoce loithont matter, 

 with no useful result. 



"Again, in a question concerning mechanical action, he says, 'When a. 

 man moves a stone by pushing it with a stick, we say both that the man 

 moves the stone, and that the stick moves the stone, but the latter more 

 properly.^ 



* Hist. Ind. Sc, Book i., chap. L 



