FALLACIES OF KATIOCINATION. 561 



§ 4. Perhaps, however, the commonest, and certainly the most danger- 

 ous fallacies of this class, are those which do not lie in a single syllogism, 

 but slip in between one syllogism and another in a chain of argument, and 

 are committed by changing the premises. A proposition is proved, or an 

 acknowledged truth laid down, in the first part of an argumentation, and 

 in the second a further argument is founded not on the same proposition, 

 but on some other, resembling it sufficiently to bo mistaken for it. In- 

 stances of this fallacy will be found in almost all the argumentative dis- 

 courses of unprecise thinkers ; and we need only here advert to one of the 

 obscurer forms of it, recognized by the school-men as the fallacy d dicto 

 secundum quid ad diction simpliciter. This is committed when, in the 

 premises, a proposition is asserted with a qualification, and the qualifica- 

 tion lost sight of in the conclusion ; or oftener, Avhen a limitation or con- 

 dition, though not asserted, is necessary to the truth of the proposition, 

 but is forgotten when that proposition comes to be employed as a premise. 

 Many of the bad arguments in vogue belong to this class of error. The 

 premise is some admitted truth, some common maxim, the reasons or evi- 

 dence for which have been forgotten, or are not thought of at the time, 

 but if they had been thought of would have shown the necessity of so lim- 

 iting the premise that it would no longer have supported the conclusion 

 drawn from it. 



Of this nature is the fallacy in what is called, by Adam Smith and oth- 

 ers, the Mercantile Theory in Political Economy. That theory sets out 

 from the oommon maxim, that whatever brings in money enriches ; or that 

 every one is rich in proportion to the quantity of money he obtains. 

 From this it is concluded that the value of any branch of trade, or of the 

 trade of the country altogether, consists in the balance of money it brings 

 in ; that any trade which carries more money out of the country than it 

 draws into it is a losing trade; that therefore money should be attracted 

 into the country and kept there, by prohibitions and bounties ; and a train 

 of similar corollaries. All for want of reflecting that if the riches of an 

 individual are in proportion to the quantity of money he can command, it 

 is because that is the measure of his power of purchasing money's worth ; 

 and is therefore subject to the proviso that he is not debarred from em- 

 ploying his money in such purchases. The premise, therefore, is only true 

 secundum quid; but the theory assumes it to be true absolutely, and in- 

 fers that increase of money is increase of riches, even when produced by 

 means subversive of the condition imder which alone money can be riches. 



A second instance is, the argument by which it used to be contended, 

 before the commutation of tithe, that tithes fell on the landlord, and were 

 a deduction from rent; because the rent of tithe-free land was always 

 higher than that of land of the same quality, and the same advantages of 

 situation, subject to tithe. Whether it be true or not that a tithe falls on 

 rent, a treatise on Logic is not the place to examine ; but it is certain that 

 this is no proof of it. Whether the proposition be true or false, tithe-free 

 land must, by the necessity of the case, pay a higher rent. For if tithes 

 do not fall on rent, it must be because they fall on the consumer ; because 

 they raise the price of agricultural produce. But if the produce be raised 

 in price, the farmer of tithe-free as well as the farmer of tithed land gets 

 the benefit. To the latter the rise is but a compensation for the tithe he 

 pays ; to the first, who pays none, it is clear gain, and therefore enables 

 him, and if there be freedom of competition, forces him, to pay so much 

 more rent to his landlord. The question remains, to what class of fallacies 



36 



