402 FALLACIES. 



passage respecting cupiditas and cupidus is also an example 

 of another fallacy already noticed, that of Paronymous 

 Terms. 



Many more of the arguments of the ancient moralists, and 

 especially of the Stoics, fall within the definition of Petitio 

 Principii. In the De Finibus, for example, which I continue 

 to quote as heing probably the best extant exemplification at 

 once of the doctrines and the methods of the schools of philo- 

 sophy existing at that time ; of what value as arguments are 

 such pleas as those of Cato in the third book : That if virtue 

 were not happiness, it could not be a thing to boast of : That 

 if death or pain were evils, it would be impossible not to fear 

 them, and it could not, therefore, be laudable to despise them, 

 &c. In one way of viewing these arguments, they may be 

 regarded as appeals to the authority of the general sentiment 

 of mankind, which had stamped its approval upon certain 

 actions and characters by the phrases referred to ; but that 

 such could have been the meaning intended is very unlikely, 

 considering the contempt of the ancient philosophers for 

 vulgar opinion. In any other sense they are clear cases of 

 Petitio Principii, since the word laudable, and the idea of 

 boasting, imply principles of conduct ; and practical maxims 

 can only be proved from speculative truths, namely from the 

 properties of the subject matter, and cannot, therefore, be 

 employed to prove those properties. As well might it be 

 argued that a government is good because we ought to sup- 

 port it, or that there is a God because it is our duty to pray 

 to him. 



It is assumed by all the disputants in the De Finibus as 

 the foundation of the inquiry into the summum bonum, that 

 " sapiens semper beatus est." Not simply that wisdom gives 

 the best chance of happiness, or that wisdom consists in 

 knowing what happiness is, and by what things it is pro- 

 moted ; these propositions would not have been enough for 

 them : but that the sage always is, and must of necessity be, 

 happy. The idea that wisdom could be consistent with 

 unhappiness, was always rejected as inadmissible : the reason 

 assigned by one of the interlocutors, near the beginning of the 



