LOGIC. Logic is that philosophical science which deals with the principles and methods of all thinking. The processes of thought, although varied in form and content, have always a single end; to interpret the past and the present, and by means of such interpre tation to forecast the future. It is by think ing that we are able the better to understand the experiences of to-day and the more wisely to prepare for the events of to-morrow. Any object of thought— a thing, a person, an event — if it is to be really grasped by the thinking mind and to become a part of our body of knowledge, must be correctly interpreted by us. And by interpretation is meant the revelation of its essential significance in the light of the universal principle or the universal nature which the particular object under investigation illustrates. The primary function of logic is this: the interpretation of the particular by means of the universal which underlies it. The development of all logical theory is merely the elaboration of this fundamental principle. To refer any object of consciousness to a universal is the sole method of describing its character istics, or expressing its significance. If, for instance, I declare a certain plant to be poison ous, I have characterized it by an adjective which admits an indefinite variety of applica tions but preserves always one and the same essential significance, and this is the meaning and the function of the universal. Any noun which stands for a class or group of objects, or any i adjective which may he variously ap plied, s a universal; or as it is technically known in logic —a concept. Moreover, the reference of any particular object of thought to a universal, i.e., to a concept which serves to interpret it, is a judgment.
Inasmuch as the reference is always con fronted with the possibility of error, it is of the very nature of a judgment to raise the question of its truth or falsity, according as the knowl edge upon which it is based is accurate or in accurate, adequate or inadequate. In the manifold conflict of opinion there is an obvious need of some definite and fundamental cri terion to discriminate between the true and the false. The final court of appeal as to the truth or the falsity of knowledge must be to the main body of knowledge as a whole. This is the test: does the new experience square with our accumulated experience or not? Truth as regards its logical significance must measure up to the supreme standard, namely, of consistency with all that constitutes'the world of knowledge as we understand it. As the judgment is the logical vehicle of expressing truth, it is natural that it should take the form of a reference of the immediate object of consciousness to the general body of knowledge which has been already received, tested and assimilated by the mind. Thus, every new experience is to be illuminated and interpreted by the old. This is the program of thought and the way of all logical procedure and progress. However, there
can be no essential progress in thought when the judgment is merely the recognition of the appropriate place of a new thought in our general body of knowledge. Progress is mani fest when the object of thought, in the light of our knowledge as a whole, gives rise to some new idea which is not expressed in the given object of thought alone, nor yet in our general body of knowledge alone, but which is neiter theless necessitated and revealed by the com bination of the two sources taken together. Our general body of knowledge contributes a part, and the given object of thought con tributes the other part. When brought together the two parts fuse into one, forming a complete whole. Thought in this sense is creative. The given elements at hand may be old, hut thought constructs them into new forms, ever adding to the store of knowledge from the very ele ments which knowledge itself furnishes. This process is the consummation of all the various logical functions and is known as the process of inference. Inference is possible because our judgments contain more knowledge than they ever express upon the surface. There is a de posit of knowledge which is implicit in every judgment, and this is due to the fact that all of our judgments are interrelated and inter dependent. The complete significance of a judgment is revealed only in the light of all its relevant and cognate judgments. The im plicit becomes explicit only when a given judg ment is brought into relation to some other judgment which has already been tested and found place in our body of general knowledge; this is what occurs in the process of inference. For instance, if it is asserted that a bar of soft iron will become a magnet if an electric current is allowed to pass through a coil of wire bound about it, such an assertion is based upon our general knowledge which is con tamed in the judgment that a current of elec tricity passing through a coil of wire always transforms an iron bar within the coil into a magnet. Without this general knowledge the mere fact of having a coil of wire wound around a piece of iron would be meaningless. To have any significance such a fact must have the light of our general knowledge brought to bear upon it. Then only does the given fact become suggestive and fertile in the increase of knowledge. Or again, if in any triangle there are given the two angles and the included side, one can infer by means of the knowledge of trigonometrical principles the other angle and the remaining two sides. Such a process of inference consists in the combination of what is given with certain general principles which constitute a part of our body of knowl edge. That which is given without the general principles to interpret and develop it in all of its implied bearings and relations would remain devoid of significance and with no value as knowledge whatsoever.