CORRESPONDENCE 



To the Editor of " Science Progress " 



LOGIC : A REJOINDER TO A REJOINDER 



S IR> — if your columns are open to correspondence I should 

 like to take up the cudgels on behalf of Miss Stebbing, who is 

 assailed by Dr. Mercier in your last issue. 



The doctor adduces four concrete examples to fortify his 

 arguments, and as the concrete is more easily handled than 

 the abstract, I will refer to them one by one. 



i . If The bed contains nothing but geraniums and violas, 

 then It contains no asters. 



This Dr. Mercier propounds as a specimen argument which 

 is not a syllogism. Miss Stebbing proceeds to show that it 

 is a syllogism of the most ordinary kind, by putting the premiss 

 in the form 



All the flowers in the bed are geraniums and violas. 



Whereupon her critic with an unnecessary amount of 

 ironical banter charges her with making a statement unsup- 

 ported by proof. Now, waiving the minor point that the 

 conjunction or should have been used instead of and, the two 

 premisses are identical. The word // with which Dr. Mercier 

 introduces his argument is the equivalent of the old English 

 gif, or give, in the sense of grant, and is understood before 

 every logical premiss. Logic takes no cognisance of the 

 truth or falsehood of a premiss. That is a question for other 

 sciences or other departments of thought. Logic merely 

 affirms that given certain premisses such and such a conclusion 

 does or does not follow. Dr. Mercier 's argument in syllogistic 

 form would then read : 



Given that everything growing in the bed is a geranium or 



viola, 



Given that no geranium or viola is an aster, 



then No aster grows in the bed. 



491 



