Page:Mind (New Series) Volume 8.djvu/111

 CARVETH BEAD, Logic, Deductive and Inductive. 97 wanted, and the illustrations are never inappropriate or trivial, though sometimes they seem to be of the nature of a joke. It has been said by a great writer on ethics that there is general agreement as to what Virtue is that "there is in reality an universally acknowledged standard of it. It is that which all ages and all countries have made profession of in public ; it is that which every man you meet puts on the show of ; it is that which the primary and fundamental laws of all civil constitutions- over the face of the earth make it their business and endeavour to enforce the practice of upon mankind." Yet as a later writer tells us " on its speculative side it has been, and it still is, the centre of apparently endless controversy the subject of every species of confusion ". And mutatis mutandis, the same paradox seems applicable in Logic, and more especially that core of De- ductive Logic which has remained in essentials unchanged from Aristotle to Mill. (How far, apart from the direct acquisition of fresh information and from metaphysical and psychological principles, it includes ' Inductive ' Logic is a point which Mr. Read seems to decide in favour of inclusion cf. p. 193.) Most of us. know, and are agreed, what good reasoning cogent syllogism or trustworthy Induction is, but why it is good, what the theory of valid inference is, is regarded as matter of doubt and difficulty. Thinkers who believe themselves to base all knowledge upon ' particulars,' and those who start from universal principles, are equally capable of estimating or discovering scientific truth ; those who insist upon the importance in logical theory of a careful and unremitting reference to context, and those who treat propositions symbolically and thus of necessity leave particularities of context out of account would for the most part be in entire agreement as to the validity or invalidity of any clearly understood argument. And those who appear to "identify" Psychology and Logic, are just as keen as others to detect an inference that is not logical. These well-worn reflections are suggested by Mr. Bead's book, partly because of the list of writers to whom he refers in his Preface, partly because he succeeds to a great extent in carrying out his intention of treating the recognised body of logical doctrine in separation from speculative theory from the more disputable matter of Psychology and Metaphysics and partly because they receive interesting though perhaps superficial illustration from comparison of the present book with the author's Theory of Logic published in 1878 and reviewed by Dr. Venn in MIND for that year. Nothing could well be more striking than the unlikeness between the two works in many respects in form, in purpose, in statement, in some theoretical explanations of accepted logical doctrines. But the logical core of both is essentially the same indeed in this case, more than the core, since in reality the same matter-of-fact view is on the whole kept, and the same school of writers adhered to. And it is further interesting to notice how both books are