mathematics; and, I believe, he may, by like means, acquire a habit of reasoning justly in mechanics, in jurifprudence, in politics, or in any other fcience. Good fenfe, good examples, and affiduous exercife, may bring a man to reafon juftly and acutely in his own profeffion, without rules.

But if any man think, that from this conceffion he may infer the inutility of logic, he betrays a great want of that art by this inference: for it is no better reafoning than this, That because a man may go from Edinburgh to London by the of Paris, therefore any other road is

way

ufelefs.

There is perhaps no practical art which may not be acquired, in a very confiderable degree, by example and practice, without reducing it to rules. But practice, joined with rules, may carry a man on in his art farther and more quickly, than practice without rules. Every ingenious artifl knows the utility of having his art reduced to rules, and by that means made a fcience. He is thereby enlightened in his practice, and works with more affurance. By rules, he fometimes corrects

his own errors, and often detects the errors of others: he finds them of great ufe to confirm his judgement, to justify what is right, and to condemn what is wrong.

Is it of no use in reasoning, to be well acquainted with the various powers of the human understanding, by which we reafon? Is it of no use, to refolve the various kinds of reasoning into their fimple elements; and to difcover, as far as we are able, the rules by which these elements are combined in judging and in reafoning? Is it of no use, to mark the various fallacies in reasoning, by which even the most ingenious men have been led into error? It must furely betray great want of understanding, to think these things uselefs or unimportant. These are the things which logicians have attempted; and which they have executed; not indeed fo completely as to leave no room for improvement, but in fuch a manner as to give very confiderable aid to our reasoning powers. That the principles laid down with regard to definition and divifion, with regard to the converfion and oppofition of propofitions and the general rules of reafoning, are not without ufe, is fufficiently

3 G 2

ciently apparent from the blunders committed by thofe who difdain any acquaintance with them.

Although the art of categorical fyllogifm is better fitted for fcholaftic litigation, than for real improvement in knowledge, it is a venerable piece of antiquity, and a great effort of human genius. We admire the pyramids of Egypt, and the wall of China, though ufelefs burdens upon the earth. We can bear the most minute, defcription of them, and travel hundreds of leagues to fee them. If any perfon fhould with facrilegious hands deftroy or deface them, his memory would be had in abhorrence. The predicaments and predicables, the rules of fyllogifm, and the topics, have a like title to our veneration as antiquities: they are uncommon efforts, not of human power, but of human genius; and they make a remarkable period in the progrefs of human reafon."

The prejudice against logic has probably been ftrengthened by its being taught too early in life. Boys are often taught logic as they are taught their creed, when it is an exercife of memory only, without underflanding. One may as well expect

to

to understand grammar before he can fpeak, as to understand logic before he can rea fon. It must even be acknowledged, that commonly we are capable of reafoning in mathematics more early than in logic. The objects prefented to the mind in this science, are of a very abftract nature, and can be distinctly conceived only when we are capable of attentive reflection upon the operations of our own understanding, and after we have been accustomed to reafon. There may be an elementary logic, level to the capacity of those who have been but little exercifed in reasoning; but the most important parts of this fcience require a ripe understanding, capable of reflecting upon its own operations. Therefore to make logic the firft branch of fcience that is to be taught, is an old error that ought to be corrected.

SECT. 2. Of the Improvement of Logic.

In compofitions of human thought expressed by speech or by writing, whatever is excellent and whatever is faulty, fall within the province, either of grammar,

or

or of rhetoric, or of logic. Propriety of expreffion is the province of grammar; grace, elegance, and force, in thought and in expreffion, are the province of rhetoric; juftnefs and accuracy of thought are the province of logic.

The faults in compofition, therefore, which fall under the cenfure of logic, are obfcure and indiftinct conceptions, false judgement, inconclufive reafoning, and all improprieties in diftinctions, definitions, divifion, or method. To aid our rational powers, in avoiding thefe faults and in attaining the oppofite excellencies, is the end of logic; and whatever there is in it that has no tendency to promote this end, ought to be thrown out.

The rules of logic being of a very abAtract nature, ought to be illuftrated by a variety of real and striking examples taken from the writings of good authors. It is both inftructive and entertaining, to obferve the virtues of accurate compofition in writers of fame. We cannot fee them, without being drawn to the imitation of them, in a more powerful manner than we can be by dry rules. Nor are the

faults of fuch writers, lefs inftructive or

lefs