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



my own explanatory excuse from the preceding paper, — I omit Mr Baynes's defence from this 

 addition. I may hereafter compare it with my own excuse, when something arises which the 

 comparison will illustrate. I also asked (Nov. 2, 186l) for information as to whether Hamil- 

 ton had given his own sense of ' some' from his chair. The silence of all his pupils on 

 this point obliged me to thinic he might actually have taught this sense of ' some' as to be 

 applied to the only forms of syllogism which I could — or can — ascertain that he had given. 

 I therefore (Oct. 18, 1862) put the question in stronger terms, and by name to Mr Baynes, 

 to Hamilton's editors, and to his successor. In taking up this point, Mr Baynes of course 

 felt it necessary to take up the others; but on this point his answer (Nov. 22, 1862) was 

 explicit and satisfactory ; as follows. " Within my experience of his class-teaching (up to 

 the close of session 1853-4), Sir William did not, that I remember, depart from the ordi- 

 nary meaning of " some" in teaching the syllogism. But for years before this he was 

 accustomed to expound briefly from the chair his doctrine of immediate inference [in which 

 one proposition only is concernedT and of course as a part of it the different meanings of 

 ' some'." Tiiis is to the purpose ; and Mr Baynes is the best living witness on the matter. 



The remaining point is that of the application of the new meaning of "some" to syllo- 

 gism. On this Mr Baynes speaks — but without a single reference in proof of his statements 

 — as follows: I put some words in Italics (Nov. 22, 1862). 



" The alleged invalidity of these syllogisms wholly depends on the use of the quantify- 

 ing term " some" in a special sense. But Prof. De Morgan offers no proof whatever that it 

 is so employed in the scheme he criticises. He states, indeed, what is perfectly true, that Sir 

 William Hamilton signalised this particular meaning and contended for its partial use. [This 

 statement is not mine.] Sir William Hamilton, in applying his new doctrine to preposi- 

 tional forms, discusses the vague generality of " some" in its ordinary use as a mark of quan- 

 tity, points out that it may be taken in a narrower or more definite sense, and proposes the 

 introduction of this new meaning " alongside of the other" in particular cases and for 

 special objects. These objects, as Sir William defines them, all relate to propositional 

 forms. Tlie partial use of the narrower " some" not only yields a complete and consistent 

 scheme of opposition, but supplies certain valuable forms of immediate inference. For these 

 reasons, Sir William introduces alongside the ordinary and vaguer " some" (some at least) the 

 more definite " some" (some at most) as a mark of quantity ; but he carefully defines the con- 

 dition, of its use, and specifies the instances in, which it is actually employed. From this 

 partial and well-defined use of the more definite " some" in the treatment of propositional 

 forms. Prof. De Morgan assumes that Sir William Hamilton not only carries it over into his 

 scheme of syllogism, but applies it to every detail of that scheme." 



In my reply (Nov. 29, 1862) I disposed of two of the Italic phrases by pointing out that 

 I had given references to the successive papers on proposition and syllogism, which, writing to 

 persons who had the book in their hands, and power to follow an implied argument in their 

 heads, I took to be quite enough. I challenged Mr Baynes to support the remaining words 

 in Italics from Hamilton's writings, stating that tiiis present paper was going to the printer, 

 and desiring to couple with my statements the fullest account of his answer. Mr Baynes, 

 acknowledging my references by substituting want of "definite proof" for statement that I 



