AND ON THE LOGIC OF RELATIONS. 355 



pose that the parties inculpated found that the ordinary syllogism does not very frequently 

 contain the act of reasoning. And in truth, when it does appear, it is usually Barbara or 

 Celarent, that is ' Species of species is species ' or else ' Species of external is external :' 

 both contained in the principle that the part follows the whole as to inclusion or exclusion. 

 Of the common logical heads, the study of the term and of the proposition, of the aggregates 

 and components of the term, and of the transformations of the proposition, is far more neces- 

 sary, presents points of far more frequent occurrence, and holds out far greater occasion 

 for warning, than the study of the syllogism, when limited to the arithmetical abacus. 



If the ordinary syllogism deserved the character given of it, a certain chapter in the 

 older books of logic, instead of dropping into desuetude, would have increased in size and 

 importance, with good assurance of addition to both. I mean the chapter De Inventione 

 Medii Termini, This part of the subject was enlarged into many heads by the latest of the 

 older writers : but in those who most resemble the genuine schoolmen, as Sanderson for ex- 

 ample, the pure heading above given is preserved and its subject treated within the limits 

 of the phrase. If all reasoning be reducible to ordinary syllogism, it follows that any asser- 

 tion inferred about two terms must arise from comparison of the two by aid of some middle 

 term, which is therefore to be investigated. Accordingly, a universal negative can only be 

 established by finding out a third, or middle, term, in which one of the terms of the conclu- 

 sion is wholly contained, and from which the other is wholly excluded. So necessarily is this 

 invention of a middle term the act of investigation, if the syllogism, as given, be what it is 

 said to be, that the mode of arrival at the missing element is very properly formalised into 

 memorial verses Fecana, Cageti, &c., which ought to have followed Barbara, Celarent, he, as 

 practice follows theory. 



When by the word syllogism we agree to mean a composition of two relations into one, 

 we open the field in such manner that the invention of the middle term, and of the com- 

 ponent relations which give the compound relation of the conclusion, is seen to constitute the 

 act of mind which is always occurring in the effbrts of the reasoning power. Was an event 

 the consequence of another? We know that consequence of consequence is consequence, 

 and, X being a suspected consequence of Z, we examine various Ys, and try if for any one 

 of them we can establish that X is a consequence of Y and Y of Z. We do not consciously 

 refer our search after relation to the notion of relation, nor our act of composition to the 

 notion of composition ; so that our descriptions of mental processes, when exhibited in tech- 

 nical terms, are as strange as our daily syntax when explained in phrases of grammar to an 

 uneducated but tolerably correct speaker. The person X, did he commit the act Z ? 

 Non-possession of motive is, taken alone, probable innocence: non-production of motive is 

 probable non-possession. We try for a motive Y, to which X is related by possession, and 

 Y to Z by sufficiency. Here are the premises — X is the possessor of the motive Y ; Y is 

 a sufficient motive to commit Z ; therefore X is the possessor of a sufficient motive to com- 

 mit Z ; and this compound relation is extensively contained in — or intensively contains — the 

 relation of ' sufficiently in connexion with the action to give the evidence of actual commission 

 a claim to consideration under ordinary notions of probability.' A very complicated concluding 

 relation; but very familiar in action both to judge, counsel, and jury. But all this is not 



