« AnteriorContinuar »
ELEMENTS OF LOGIC.
Logic, in the most extensive sense which Definition of the name can with propriety be made to bear, may be considered as the Science, and also as the Art, of Reasoning. It investigates the principles on which argumentation is conducted, and furnishes rules to secure the mind from error in its deductions. Its most appropriate office, however, is that of instituting an analysis of the process of the mind in Reasoning; and in this point of view it is, as has been stated, strictly a Science : while, considered in reference to the practical rules above mentioned, it may be called the Art of Reasoning. This distinction, as will hereafter appear, has been overlooked, or not clearly pointed out by most writers on the subject ; Logic having been in general regarded as merely an Art; and its claim to hold a place among the Sciences having been expressly denied.
Prevailing Mistakes respecting Logic.
Considering how early Logic attracted the attention of philosophers, it may appear surprising that so little progress should have been made, as is confessedly the case, in developing its principles, and perfecting the detail of the system; and this circumstance has been brought forward as a proof of the barrenness and futility of the study. But a similar argument might have been urged with no less plausibility, at a period not very remote, against the study of Natural Philosophy; and, very recently, against that of Chemistry. No science can be expected to make
which is not cultivated on right principles. Whatever may be the inherent vigour of the plant, it will neither be flourishing nor fruitful till it meet with a suitable soil and culture: and in no case is the remark more applicable than in the present; the greatest mistakes having always prevailed respecting the nature of Logic, and its province having in consequence been extended by many writers to subjects with which it has no proper connexion. Indeed, with the exception of Aristotle, (who is himself not entirely exempt from the errors in question,) hardly a writer on Logic can be mentioned who has clearly perceived, and steadily kept in view throughout, its real nature and object. Before his time, no distinction was drawn between the science of which we are speaking, and that
which is now usually called Metaphysics; a circumstance which alone shows how small was the progress made in earlier times. Indeed, those who first turned their attention to the subject, hardly thought of inquiring into the process of Reasoning itself, but confined themselves almost entirely to certain preliminary points, the discussion of which is (if logically considered) subordinate to that of the main inquiry.
Zeno the Eleatic, whom most accounts re- Early writers present as the earliest systematic writer on the subject of Logic, or, as it was then called, Dialectics, divided his work into three parts ; the first of which (upon consequences) is censured by Socrates [Plato, Parmen.] for obscurity and confusion. In his second part, however, he furnished that interrogatory method of disputation [épornois) which Socrates adopted, and which has since borne his name. The third part of his work was devoted to what may not be improperly termed the art of wrangling [épLotin), which supplied the dis
utant with a collection of sophistical questions, so contrived, that the concession of some point which seemed unavoidable, immediately involved some glaring absurdity. This, if it is to be esteemed as at all falling within the province of Logic, is certainly not to be regarded (as some have ignorantly or heedlessly