PRINCIPLES OF LOGIC BY HERBERT AUSTIN AIKINS, PH.D. PRINCIPLES OF LOGIC BY HERBERT AUSTIN AIKINS, PH.D. BH 474 1382 PREFACE. THE deductive part of this book may require a few words of explanation. In most text-books on logic deduction and induction are treated from two very different standpoints. Induction is regarded as a means for the investigation of nature, and its canons are frankly objective or material'. They tell us how things must be related to each other in one respect if they are also ́related in some other respect (e.g., how two events must be related in time if one is the cause of the other); and they do not say anything about the relation of our thoughts to each other as mere thoughts, or give any rules for the arrangement and manipulation of the words in which these thoughts are expressed. 66 Deduction, on the other hand, is usually defined as the "science of the laws of thought "-as one writer says, its object-matter is thought ",-and it is treated altogether from the subjective or formal' standpoint, as though mere thoughts as such could be consistent or inconsistent, wholly regardless of the nature of the object to which they refer; and then, when it comes to working out the details of the subject from this standpoint, the laws of thought' are treated practically as though they were laws for the right arrangement and manipulation of words. Hence we have rules of the syllogism and allied rules for conversion and obversion which say nothing whatever about the things under discussion and their relations to each other, but tell us only how we must or must not arrange our words in disussing them. |