Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 1, 1802).djvu/125

Rh logic, signifies an inference drawn from premises, the truth of which is either indisputable, or highly probable. In matters of literature, it denotes the abridgement, or heads, of a book, history, chapter, &c. Considered in the former sense, in which it solely relates to reason, and to the investigation of truth, it is, in its principles, of a simple and homogeneous nature; and requires no particular explanation. For, pleasure being the chief end of poetry, and persuasion that of eloquence, the real constitution of things is often perverted, or disguised, and compelled to adapt itself to the imagination and the passions; but truth, being the ultimate object of argument, stands in need of no dazzling colours, or the figurative language of rhetoric.

It is not, however, unusual (both in private life and in the senate) to draw from an argument, a conclusion very different from what it really implies. Cunning and bold disputants frequently avail themselves of ambiguous expressions, which easily engender a confusion or ideas; and thus the fallacy of their incongruous reasoning but too often escapes detection, as it remains involved in sophistical perplexity.—For a farther consideration of this interesting subject, we refer our readers to the article of, where it will be more applicable than under the present.  Aristolochia. See.  ARITHMETIC, is a science which teaches the method of computing numbers, and explains their nature and peculiarities. At what time it was invented, is altogether unknown; though the four first fundamental principles, viz. addition, subtraction, multiplication, and division, have always, in a certain degree, been practised by different nations.

The Greeks were among the first who brought arithmetic to perfection; and they are supposed to have originally made use of pebbles in their calculations. The most complete method of numbering now used in this country, was introduced into Europe by the Arabians, when they were in possession of Spain. These people, however, acknowledged that they derived their information from the Indians. How the latter became acquainted with it, we are entirely ignorant. The earliest treatises extant upon the theory of arithmetic, are, the 7th, 8th, and 9th books of 's Elements, in which he treats of proportion; of prime and composite numbers. , the Pythagorean, also wrote concerning the distinctions and divisions of numbers into classes, as plain, solid, triangular, &c.; in which he explained some of the leading peculiarities of the several kinds.

As learning advanced in Europe, the knowledge of numbers also increased, and the writers on this subject soon became numerous. was the first who, in his Treatise on Arithmetic, published in 1586, used decimal periods, for reducing the square and cube roots to fractions; but the greatest improvement which the art of computation ever received, was from the invention of logarithms, the honour of which is due to, Baron of Merchiston, in Scotland, who published his discovery about the beginning of the 17th century.

Arithmetic may now be considered as having advanced to a degree of perfection which, in former times, could scarcely have been