Imperative Sentences

Abstract

It has often been taken for granted by logicians that there is a class of sentences which is the proper subject-matter of logic, and that they are at liberty to ignore all sentences which are not included in this class. For example, most logicians would undertake to tell you something about the sentence ‘It is raining’; for instance, that it contradicted the sentence ‘It is not raining’; but if confronted with the sentence ‘What a foul day it is!’ they would be likely to look down their noses and refuse to say anything about the logic of such a sentence. This would seem a natural attitude to adopt. But it is much more difficult to say precisely what are the criteria which determine whether or not a sentence is to be admitted into the logical fold. This article is an attempt to cast doubt upon one such criterion which has been popular recently, and in so doing to shed some light on the question, ‘What is Logic about ?’