LOGIC

From Agepedia

LOGIC (Aoy.o?, i. e. hurrm?,); the science of the laws o 'nought, and the correct connexion of ideciS. It is not certain, however, whether the name was derived originally from thought or from language, because both may be designated by \6yog, i. e. reason and word. In German, this science has also been called DenkLehre, or VerstandesLehre (rule of thinking, or rule of the understanding), because logic strives to represent, in a scientific way, those laws which the understanding is bound to follow i in thinking, and without the observance of which, no correct conclusions are possible. Logic is valuable, not only as affording rules for the practical use of the understanding, but also as a science preparatory to all other sciences, particularly mental philosophy, as it affords the rules for giving scientific connexion to all knowledge, the laws of thinking determining the character of scientific arrangement. But, inasmuch as the laws of logic can only determine the form of our knowledge, but can by no means teach us how to obtain the materials of knowledge, and gain a clear insight into things (which is the business of mental philosophy, properly so called), in so far logic has been, of late, separated from intellectual philosophy. But if, as is not unfrequently done, all sciences are divided into the historical (those which proceed from experience, as history, natural philosophy, medicine, &c.) and the philosophical (the subjects of which do not fall within the domain of experience), logic is a philosophical science, because the laws of the connexion of thoughts and ideas are founded in reason itself, and not in experience, and the sub jects of logic are, therefore, capable of a demonstrative certainty beyond those of any other philosophical science. Logic has not unfrequently been overvalued, particularly by the ancient philosophers. It should be always kept in mind, that the most systematic order, alone, does not render assertions truth. The province of logic has been enlarged or restricted by different philosophers. Among the ancients, logic was made to include the deeper philosophical investigation of the general characteristics of truth, or the essential conditions of the truth of our knowledge, which some modern philosophers have referred to metaphysics. Logic may be divided into the pure and the applied; the former treats of the general laws and operations of thought (conceiving, judging, concluding), and their products (notion, judgment, conclusion). Applied logic treats of thought under particular and special relations, which are to be taken into consideration in applying the general laws of thought, viz. the connexions of thought with other operations of the mind, and the impediments and limitations which it thereby experiences, as, also, the means of counteracting them. For the first scientific treatment of logic, we are to look to the Greeks. Zeno of Elea is called the father of logic and dialectics ; but it was then treated with particular reference to the art of disputation, and Soon degenerated into the minister of sophistry. The sophists and the Megarean school (founded by Euclid of Megara) greatly developed this art. The latter, therefore, became known under the name of the heuristic or dialectic school, and is famous for the invention of several sophisms. The first attempt to represent the forms of thinking, in abstracto, on a wide scale, and in a purely scientific manner, was made by Aristotle. His logical writings were called, by later ages, organon, and for almost two thousand years after him maintained authority in the schools of the philosophers. His investigations were directed, at the same time, to the criterion of truth, in which path Epicurus, Zeno, the founder of the stoic school, Chrysippus and others followed him. Logic, or dialectics, enjoyed great esteem in later times, particularly in the middle ages, so that it was considered almost as the spring of all science, and was taught as a liberal art from the eighth century. The triumph of logic was the scholastic philosophy (which was but a new form of the ancient sophistry); and theology, particularly, became filled with verhaj subtilties. Raymundus Lullus strove to give logic another form. The scholastics were attacked by Campanella, Gassendi, Peter Ramus (Pierre de la Ramie), Bacon and others with wellfounded objections. Descartes and Malebranche again confounded logic and metaphysics. Locke, Leibnitz and Wolf, Tchirnhausen, Thomasius, Crusius, Ploucquet, Lambert (in his New Organon), Reimarus and others, have rendered great service to modern logic. Kant, Fichte, Schelling, Hegel, have maintained very various opinions on the subject. Whateley's Treatise on Logic, .first published in the Encyclopaedia Metropolitan, and since in a separate volume, is one of the best treatises, in English, on the subject.