that the former are expreffed in an appropriated language, with which we are not accustomed to affociate particular notions. Hence they exhibit the efficacy of figns as an inftrument of thought in a more diftinct and palpable manner, than the fpeculations we carry on by words, which are continually awakening the power of Conception.

When the celebrated Vieta fhewed algebraists that, by fubftituting in their investigations letters of the alphabet, inftead of known quantities, they might render the folution of every problem fubfervient to the discovery of a general truth, he did not increafe the difficulty of algebraical reafonings: he only enlarged the fignification of the terms in which they were expreffed. And if, in teaching that fcience, it is found expedient to accuftom ftudents to folve problems by means of the particular numbers which are given, before they are made acquainted with literal or fpecious arithmetic, it is not because the former proceffes are lefs intricate than the latter, but because their fcope and utility are more obvious, and becaufe it is more easy to illuftrate, by examples than by words, the difference between a particular conclufion, and a gene. ral theorem.

The difference between the intellectual proceffes of the vulgar and of the philofopher, is perfectly analogous to that between the two ftates of the algebraical art before and after the time of Vieta; the general terms which are used in the various fciences, giving to thofe who can employ them with correctness and dexterity, the fame fort of advan

tage

tage over the uncultivated fagacity of the bulk of mankind, which the expert algebraift poffeffes over the arithmetical accomptant.

If the foregoing doctrine be admitted as juft, it exhibits a view of the utility of language, which appears to me to be peculiarly ftriking and beautiful; as it fhews that the fame faculties which, without the use of figns, muft neceffarily have been limited to the confideration of individual objects and particular events, are, by means of figns, fitted to embrace, without effort, thofe comprehensive theorems, to the difcovery of which, in detail, the united efforts of the whole human race would have been unequal. The advantage our animal ftrength acquires by the use of mechanical engines, exhibits but a faint image of that increase of our intellectual capacity which we owe to language.—It is this increase of our natural powers of compre hension, which seems to be the principal foundation of the pleasure we receive from the discovery of general theorems. Such a difcovery gives us at once the command of an infinite variety of particular truths, and communicates to the mind a fentiment of its own power, not unlike to what we feel when we contemplate the magnitude of those phyfical effects, of which we have acquired the command by our mechanical contrivances.

It may perhaps appear, at firft, to be a farther confequence of the principles I have been endeavouring to establish, that the difficulty of philofophical difcoveries is much less than is commonly imagined; but the truth is, it only follows from

them, that this difficulty is of a different nature from what we are apt to fuppofe, on a fuperficial view of the fubject. To employ, with skill, the very delicate inftrument which nature has made effentially fubfervient to general reasoning, and to guard against the errors which result from an injudicious ufe of it, require an uncommon capacity of patient attention, and a cautious circumfpection in conducting our various intellectual proceffes, which can only be acquired by early habits of philofophical reflexion. To affift and direct us in making this acquifition ought to form the most important branch of a rational logic; a fcience of far more extenfive utility, and of which the principles lie much deeper in the philofophy of the human mind, than the trifling art which is commonly dignified with that name. The branch in particular to which the foregoing obfervations more immediately relate, muft for ever remain in its infancy, till a moft difficult and important defideratum in the history of the mind is fupplied, by an explanation of the gradual fteps by which it acquires the use of the various claffes of words which compofe the language of a cultivated and enlightened people. Of fome of the errors in reasoning to which we are expofed by an incautious ufe of words, I took notice in the preceding Section; and I fhall have occafion afterwards to treat the same subject more in detail in a fubfequent part of my work.

SECTION VI.

Of the Errors to which we are liable in Speculation, and in the Conduct of Affairs, in confequence of a rash Application of general Principles.

IT appears fufficiently from the reasonings which

I offered in the preceding Section, how important are the advantages which the philofopher acquires, by quitting the ftudy of particulars, and directing his attention to general principles. I flatter myself it appears farther, from the fame reasonings, that it is in confequence of the ufe of language alone, that the human mind is rendered capable of these comprehensive speculations.

In order, however, to proceed with fafety in the ufe of general principles, much caution and addrefs are neceffary, both in establishing their truth, and in applying them to practice. Without a proper attention to the circumftances by which their application to particular cafes must be modified, they will be a perpetual fource of mistake, and of difappointment, in the conduct of affairs, however rigidly juft they may be in themselves, and however accurately we may reafon from them. If our general principles happen to be falfe, they will involve us in errors, not only of conduct but of speculation; and our errors will be the more nume

rous, the more comprehenfive the principles are on which we proceed.

To illuftrate these observations fully, would lead to a minuteness of difquifition inconfiftent with my general plan; and I fhall therefore, at prefent, confine myself to fuch remarks as appear to be of most effential importance.

And, in the first place, it is evidently impoffible to establish folid general principles, without the previous study of particulars: in other words, it is neceflary to begin with the examination of individual objects, and individual events; in order to lay a ground-work for accurate claffification, and for a juft investigation of the laws of nature. It is in this way only that we can expect to arrive at general principles, which may be fafely relied on, as guides to the knowledge of particular truths and unless our principles admit of fuch a practical application, however beautiful they may appear to be in theory, they are of far lefs value than the limited acquifitions of the vulgar. The truth of thefe remarks is now fo univerfally admitted, and is indeed fo obvious in itself, that it would be fuperfluous to multiply words in fupporting them; and I fhould fcarcely have thought of ftating them in this Chapter, if fome of the most celebrated philofophers of antiquity had not been led to difpute them, in confequence of the mistaken opinions which they entertained concerning the nature of univerfals. Forgetting that genera and Species are mere arbitrary creations which the human mind forms, by withdrawing the attention from the dif tinguishing