LOGIC. 



Or else it is determined demonstrative- 

 ly ; so the proposition, " the opposite 

 angles made by right lines crossing each 

 other are equal," is not intuitive, but re- 

 quires to be demonstrated by a succes- 

 sion of axioms connected together : 



Or lastly, it is determined analogically, 

 upon the probability that what has,, hap- 

 pened will, in like circumstances, happen 

 again. Thus, upon the probability that 

 bodies will continue to fall to the ground ; 

 that violent motion will be followed by 

 heat ; that similar inducements or motives 

 will be followed by similar acts in men ; 

 we found the doctrine of cause and effect, 

 and establish our knowledge of physical 

 and moral history, so as to give credit to 

 the past, and confidence in many respects 

 to the future. 



It is evident that analogical propositions 

 have much less certainty than those of in- 

 tuition or demonstration. 



Though in our investigations of truth 

 we must necessarily have recourse to ob- 

 servations of individual objects and events, 

 as the ground work of all; yet, in our in- 

 ductions, reasonings, proofs, and pro- 

 cesses of instruction, we proceed from 

 generals to individuals. And as, in strict 

 demonstration, the subject and predicate 

 of a proposition are connected by a train 

 of axioms, so, in every other argumenta- 

 tion, it will be the endeavour of a wise 

 man to follow the same course as nearly 

 as may be possible. But, from the con- 

 fusion arising from the relations of the 

 complicated objects of social intercourse, 

 and from the rapidity of language with its 

 abridgments and transpositions, so many 

 things are left to be understood that it 

 is not often an easy task to show, whether 

 the reasoner does really pursue the course 

 of pure argumentation, or whether he de- 

 ceives himself or others. Logicians have 

 therefore adopted a formal arrangement 

 for each of the steps of comparison, which 

 they call a syllogism; not calculated in- 

 deed tor the discovery of remote truths 

 from the use and application of the more 

 immediate or intuitive, but well calculated 

 to give regularity to the mind by scien- 

 tific discipline, and to shorten controversy, 

 by a clear detection of the component 

 parts of false reasoning. And here, by 

 the way, it may be remarked, that the 

 inexplicable disorder of the logical rea- 

 sonings of the middle ages is less to be 

 attributed to the nature of their science of 

 reasoning, loaded as it was with needless 

 distinctions, than to their theological and 

 psychological dogmas, and the delusions 

 into which they wandered with regard to 



the objects called transcendental ; delu- 

 sions, vvliich a sound and bold application 

 of their own science, it" it could have been 

 dared, would not have confirmed, but 

 overthrown. 



But to return ; the syllogism consists 

 of three propositions. In the first, called 

 the major proposition, something is pre- 

 dicated of a general subject : in the se- 

 cond, called the minor, the subject of the 

 major becomes the predicate of a spe- 

 cific subject : and in the third, called the 

 conclusion, the predicate of the general 

 subject is applied to the specific. Thus, 



Major. All men are fallible. 



Minor. The Pope is a man ; 



Conclusion. Therefore the Pope is fal- 

 lible. 



The major and minor terms are often 

 called the premises, and the minor is 

 sometimes called the argument. The 

 premises are supposed to be intuitive, or 

 at least incontestable, and the conclusion 

 is established upon the axiom, that what- 

 ever can be predicated or affirmed of a 

 genus, may also be predicated of every 

 species comprehended under it ; and the 

 like of species, and the individuals com- 

 prehended under them. 



It is usual to denominate the two sub- 

 jects, and the predicate, terms of the syl- 

 logism The generic word or sentence 

 is called the middle term ; its predicate is 

 the major term ; and the specific word or 

 sentence is called the minor term. Thus, 

 in the preceding syllogism tUe three 

 terms are 



Major term. Fallible. 



Middle term. All men. 



Minor term. The Pope. 



Here it is not pretended, that all men 

 should upon every occasion reason ac- 

 cording to the rules of logic, any more 

 than that a writer should upon all occa- 

 sions insert each individual member of a 

 sentence, and leave nothing to be sup- 

 plied or understood But as the man 

 who is a sound grammarian can analyse 

 and parse every member of a sentence, 

 and will write with order, precision, and 

 correctness ; so will the logician, who is 

 able to arrange the parts of an argument 

 in mood and figure, be quick in discern- 

 ing the imperfect, defective, or inadmissi- 

 ble assertions, and will so dispose his 

 own notions and principles, that his proofs 

 shall be conclusive and clear The works 

 even of mathematical writers would, in 

 many instances, be benefitted by this 

 severity of conduct ; and there are fevr 

 indeed which might not be rendered more 



