Mr DE morgan, ON THE SYLLOGISM, No. V. 



429 



by Professors Mansel and Veitch, with various additions from the scattered papers of 

 the author, I have had what till then I never had, the means of knowing with precision 

 what the system is which has led me into fourteen years of controversial thought and writing: 

 how this occurred will presently appear. The whole dispute differs from many others by an 

 inversion of character. It often happens that a contest of principles degenerates into a duel : 

 but that which I speak of took its rise in personal accusation, and was gradually refined and 

 sublimated into a legitimate war of systems ; perhaps because there was a mathematician on 

 one side of it. Logic affirmed that Mathematics could not understand her principles, far 

 less extend their development : that Mathematics was a cracker of shells who could not 

 even so get at the kernels ; having no more merit than belongs to those who walk straight 

 in a ditch. Mathematics replied, in effect, that she could understand and would cultivate 

 the field of Logic : that Philosophy, which confessedly could not bite the kernel, had settled 

 nothing ; while she had at least cracked the shell : and that, while she herself could either 

 find or cut straight ditches, the only ditch in which Philosophy and Psychology had allowed 

 Logic to walk — that into which tiie blind lead the blind — was one in which, for good reason, 

 there was no walking straight at all. Such a suit is not abated by the death of one of 

 the original parties : for it concerns undying things, and the undying part of persons. 

 Hamilton's mode of controversy was conspicuously ad hominem: the adverse mind was his 

 field of psychological observation : his ways and means lay very much in inference from 

 his opponent's alleged errors to his opponent's intellectual organization. Though I need 

 not follow the example all lengths, its existence will allow me a liberty of nearer approach 

 than I should of my own mere motion have taken ; and this liberty may be used with 

 advantage to the subject. Character and motive being left untouched, I hardly see how 

 such freedom can be entirely avoided : anatomists may fight a theory upon a third body; 

 but psychologists are compelled to make some dissection of each other. 



In order that I might finally dispose of Hamilton's system of enunciation and of 

 syllogism, I found it expedient to challenge contradiction of a very curious assertion by 

 appeal to a literary journal. It was necessary that I should somewhere state, and prove 

 from the posthumous papers, that my distinguished opponent, the great logical teacher of 

 his day, had actually laid down, as valid syllogisms, forms of argument which were mere 

 paralogisms. I could not expect permission to originate such an assertion in these Trans- 

 actions: though the Society may disavow all sanction of the facts and opinions to which 

 it gives currency, leaving the responsibility on their authors, yet there are extremes both 

 of fact and of opinion which the disavowal will not reach. Nor could I forget that my 

 opponent had taken pains to put the Society and the University itself into the position 

 of parties to the discussion, so far as it lay with him to compel their appearance. He 

 had in fact refused, not merely to the Society, but to the whole academic body, from 

 the Chancellor downwards, all escape from responsibility for my logical' heresies, I there- 



' At the beginning of the article in the Disciisaions, pre- 

 ■ently noted, Hamilton gays, — " If, as has been said, Mr De 

 Morgan's Memoir may represent the Transactions, the Trans- 

 actions the Society, and the Society the University of Cam- 



bridge, then, either is the knowledge of Logic, — even of " Logic 

 not its own," — in that seminary now absolutely null, or I am 

 publicly found ignorant of the very alphabet of the science 

 I profess. The alternative I am unable to disown ; the deci- 



