statements; nor off it, by the second.” Yet from the want of any systematic mode of treating such a question only five or six of some hundred and fifty students could succeed in so simple a problem.
By symbolic statement the problem is instantly solved. Taking
the premises are evidently
The class C or shareholders may in respect of A and B be developed into four alternatives,
But substituting for A in the first and for B in the third alternative we get
The first, second, and fourth alternatives in the above are self-contradictory combinations, and only these; striking them out there remain
the required answer. This symbolic reasoning is, I believe, the exact equivalent of Mr. Venn’s reasoning, and I do not believe that the result can be attained in a simpler manner. Mr. Venn adds that he could adduce other similar instances, that is, instances showing the necessity of a better logical method.
Abbreviation of the Process.
Before proceeding to further illustrations of the use of this method, I must point out how much its practical employment can be simplified, and how much more easy it is than would appear from the description. When we want to effect at all a thorough solution of a logical problem it is best to form, in the