CLASS THE FOURTH. PHILOSOPHY. CHAPTER I. Logic, or the right Ufe of Reafon. IT is a very great error for any one to suppose, that Logic confifts only in those formal debates and verbal difputations, in which the schoolmen and their followers confumed fo much time in the dark ages, previous to the revival of claffical learning. It is equally erroneous to imagine, that it is merely intended to teach the method of disputing by rules, and to inftruct a young man to converse, not from a love of truth, but a defire of victory. As there is nothing more difingenuous than fuch a conduct as this, nothing more unbecoming a rational being, than to oppofe fophiftry to good sense, and evafsion to found argument, the logician difclaims this abuse of the principles of his art, and vindicates its rights by displaying its true and proper office. It is in reality capable of affording the most important affiftance to the understanding in its inquiries after truth; it is eminently useful in the common affairs of life, and renders the greatest service to science, learning, virtue, and religion. Logic is the art of making a proper use of the faculties of the mind in the difcovery of truth by reafon, and the communication of truth by language. Logic traces the progrefs of all our information, from our first notions of things to those numerous conclufions which refult from comparing them together. It diftinguithes the different kinds of our ideas, difcovers the caufes of our intellectual mistakes, and fhows us how we may correct them. It teaches us thofe rules which we follow, although imperceptibly, whenever we think in a manner conformable to truth. By truth is meant the agreement of our ideas with the real ftate of things. "It is the offspring of unbroken meditations, and of thoughts often revised and corrected." The love of truth is the pureft principle of our nature, and prompts us to the moft noble exercife of the understanding. It frees us from the mifts of prejudice, the fluctuations of doubt, and the perplexities of error. When nothing influences, nothing agitates, nothing dazzles us in comparifon with this love, we become gradually more eager for ftrong and clear evidence, and we leave no method untried, which can conduct us to right conclufions. In the definition of logic, when we fpeak of the faculties of the mind, we include under those terms, the memory, the fancy, and the judgment. * Wollafton. The The word reafon, likewife, when used in contradiftinction to instinct, denotes them all. Reason, ufed in this fenfe, is the pre-eminent quality by which mankind are diftinguished from other animals: but still we are far from finding that all men poffefs it in the fame degree. There is, indeed, as great an inequality in this refpect, in different persons, as there is in their strength and agility of body. Nor ought this difproportion to be wholly ascribed to the original conftitution of their minds; it may be owing to habit, education, and government; for if we take a furvey of the nations of the world, we fhall find that fome men, as the favages of Africa and America, are immerfed in ignorance and barbarifm; others, as many of the inhabitants of Europe, are enlightened by learning and fcience; and what is ftill more extraordinary, the people of the fame country have been, in various ages, marked by thefe very opposite characters; take, for example, the ancient and modern inhabitants of Italy, Greece, Arabia, and Egypt. It is, therefore, by due cultivation and perfevering diligence only, that we can increase the native vigour of our minds, and carry reason to a high degree of improvement. Where this method is followed, men extend their knowledge in every direction; where it is neglected, they remain ignorant of their own powers; and thofe faculties by which Providence has enabled them to examine its wonderful works, to inveftigate the causes of things, and to arrive at the most important conclufions as to their welfare and happiness, remain ufelefs and uncultivated". Logic is divided into four parts. I. Simple Apprehenfion. II. Judgment. III. Reasoning. IV. Method. Simple apprehenfion, or perception, is the first operation of the mind. It is the power of acquiring fimple ideas, such as of a horse, a tree, a body, a foul, high, low, rich, poor, &c. The impreffions made upon the mind by these objects and qualities, are called ideas. The fources of knowledge by which the mind is fupplied with all its materials for thinking are two, which are fenfation and reflection. Senfation is the fource of our original ideas, and includes all the notices conveyed into the mind by impulfes made upon the organs of the fenfes. Such are the ideas of white, black, hard, foft, bitter, and fweet, and all thofe which are called fenfible qualities. We derive all fuch ideas from external objects. The other fource of ideas arifes from the attention of the mind to its own internal operations; * Almoft the whole of this chapter is compiled from Locke's Effay on the Human Understanding, Watts's Logic, and Dodley's Preceptor. I have endeavoured to reduce the fubject to its fimpleft principles; and thofe who wish to view it complete, in all its technical forms, and particular branches, are referred to the concife treatife of Aldrich, and the more perfpicuous work of Wallis. fuch fuch as thinking, doubting, hoping, fearing, &c. Thefe ideas we receive into our understandings as diftinctly as we receive ideas from bodies, which affect the fenfes. This fource of knowledge is called Reflection. A proper confideration of these two fources of our thoughts will give us a clear and diftinct view of the nature of the mind, and the first steps it takes in the path of knowledge. From these fources all our discoveries derive their origin; for the mind thus stored with its original notices of things, has a power of combining and modifying them, by which means it is enabled to multiply its objects, and finds itfelf poffeffed of an inexhauftible stock of materials for thinking. In the various comparifons of these ideas, we exert ourselves in the acts of judging and reasoning, enlarge our mental profpects, and can extend them in every direction. Thus are we enabled to form a notion of the whole progrefs of the foul, from the firft dawnings of thought to the utmoft limits of human knowledge; from the first perceptions of a child to the moft refined and complicated reafonings of a Newton. The ideas, with which the mind is thus furnished, fall naturally under two heads. First, thofe original impreffions which are conveyed by fenfation and reflection, and which exift uniformly and without any shadow of variety, and are called fimple ideas, such are the ideas of colour, found, heat, &c. And, fecondly, thofe notions which refult from the va |