FALLACIES OF CONFUSION. 516 



proving. He says, jnhius multlplictl by 7ninus cannot give minus; for 

 minus multiplied by j>lus gives minus, and minus nmltiplicd by minus 

 cannot give the same product as minus multi])licd by ])lus. Now one 

 is obliged to ask, wliy minus multiplird ])y minus must give any pro-, 

 duct at all I and if it does, wliy its pioduct caimot be the same as that 

 of minus multiplied by plus? for this would seem, at the first glance, 

 not more absurd than that minus by minus should give the same as 

 plus by plus, the proposition whlcli Euler prefers to it. The premiss 

 requires proof, as much as the conclusion : nor can it be proved, except 

 by tliat more comprehensive view of the nature of multiplication, and 

 of algebraic processes in general, which would also supply a far better 

 proof of the mysterious doctrine which Euler is here endeavoring to 

 demonstrate. 



A very striking instance of reasoning in a circle is that of some ethical 

 philosophers, who first take for their standard of moral truth what, being 

 the general, they deem to be the natural or instinctive, sentiments and 

 perceptions of mankind, and then explain away the numerous instances 

 of divergence from their assumed standard by representing them as 

 cases in which the perceptions are unhealthy. Some particular mode 

 of conduct or feeling is affirmed to be unnatural ; why? because it is 

 abhorrent to the universal and natural sentiments of mankind. Find- 

 ing no such sentiment in yourself, you question the fact; and the 

 answer is (if your antagonist is polite) that you are an exception, a 

 peculiar case. But neither (say you) do I find in the people of some 

 other country, or of some former ago, any such feeling of abhorrence ; 

 "aye, but their feelings were sophisticated and unhealthy." 



One of the most notable specimens of reasoning in a circle is the 

 doctrine of Hobbes, Rousseau, and others, which rests tlie obligations 

 by which human beings are bound as members of society, upon a sup- 

 posed social compact. I wave the consideration of the fictitious nature 

 of the compact itself; but when a philosopher (as Hobbes does through 

 the whole Leviathan) elaborately deduces the obligation of obeying 

 the sovereign, not from the necessity or utility of doing so, but from a 

 promise supposed to have been made by our ancestors, on renouncing 

 savage life and agreeing to establisli a political society, it is impossible 

 not to retoit by the question, why are we bound to keep a promise 

 made for us by others I or why bound to keep a promise at all ? No 

 satisfactoiy ground can be assigned for the obligation, except the mis- 

 chievous consequences of the absence of faith and mutual confidence 

 among mankind. We are, therefore, brought round to the interests of 

 society, as the ultimate ground of the obligation of a promise; and yet 

 those interests are not admitted to be a sufficient justification for the 

 existence of government and law. Witliout a promise it is thought 

 that we should not be bound to that without which tlio existence of 

 society would be impossible, namely, to yield a general obedience to 

 the laws therein established ; and so necessary is the promise deemed, 

 that if none has actually been made, some additional safety is supposed 

 to be given to the foundations of society by feigning one. 



§ 3. Two principal subdivisions of the class of Fallacies of Con- 

 fusion having been disposed of; there remains a third, in whioh the 

 confusion is not, as in the Fallacy of Ambiguity, in misconceiving the 

 import of the premisses, nor, as in Pctitio Principii, in forgetting what 



