see Sir W. Hamilton's Lectures on Metaphysics, Lect. xxxiii. The creations of poetry and art are results of complex imagination, or, in other words, of repeated processes of simple imagination and comparison. Inasmuch as complex imagination may be analysed into simple imagination and comparison, and is thus not one of the ultimate acts or operations to which our mental phenomena are traceable, it would have been beside my purpose to have noticed it in the text. Note 3.-I have employed the expression act or operation,' avoiding the expression 'power or faculty,' as the latter implies a theory of mental phenomena which would be rejected by many psychologists. It has been necessary to speak of 'act or operation,' as the word 'act,' like many other terms of logic or psychology, may mean either the operation or the result. This is an instance at the very outset of the ambiguity noticed in the paragraph at the end of the preface. CHAPTER II. Definition of Logic. IT is the province of Logic to distinguish correct from incorrect thoughts, i. e. to analyse those thoughts which are accepted by mankind as indubitably correct, and to point out wherein they differ from those which are regarded as doubtful or incorrect; and, as a consequence of this function, it is also its province to lay down rules for the attainment of correct thoughts and for the avoidance of incorrect thoughts. Thus Logic is both a Science and an Art. It is a Science, inasmuch as it furnishes us with a knowledge of what is, inasmuch as it is an analysis, and determines the conditions on which valid thoughts depend. It is an Art, inasmuch as it lays down rules for practice, and thus enables us to detect incorrect thoughts in the reasonings of others, and to avoid them in our own. Logic may therefore be defined as the science of the conditions on which correct thoughts depend, and the art of attaining to correct and avoiding incorrect thoughts. Note. This definition is in substance that given by Mr. Mill in his Examination of Sir W. Hamilton's Philosophy, p. 391 (third ed., p. 448). 'Logic,' he says, 'is the art of thinking, which means of correct thinking, and the science of the conditions of correct thinking.' The word 'thoughts' is substituted for 'thinking,' in order to bring more prominently before the student, what Mr. Mill himself acknowledges, the fact that Logic is concerned with the products or results rather than with the process of thought, i.e. with thoughts rather than with thinking, though, in estimating the conditions on which correct thoughts depend, it is necessary, to some extent, to take account of the processes by which they are formed. It seems also desirable to introduce into the definition of Logic some reference to incorrect thoughts,' as bringing out more distinctly the character of Logic as an art, and asserting for it the right of investigating fallacies. CHAPTER III. On the Relation of Thought to Language. WHETHER it is possible to think without the aid of language, is a question which has been a constant source of dispute amongst logicians and psychologists. It is not necessary, however, here to enter on this discussion. As all logicians are agreed that we cannot communicate our thoughts without the aid of language, or of equivalent signs, and that practically we do always think by means of language, by a sort of internal converse, it will be safer to adopt the terminology of those authors who regard our thoughts as expressed in language rather than that of those who consider or attempt to consider them in themselves as apart from their expression in words. I shall therefore speak of Terms and Propositions, not of Concepts and Judgments. Note.-Sir W. Hamilton and his followers, regarding Logic as primarily and essentially concerned with thought, and only secondarily and accidentally with language, attempt to mark the products of thought by words which do not imply their expression in language. Thus, instead |