a fentiment of its own power, not unlike to what we feel when we contemplate the magnitude of those physical effects, of which we have acquired the command by our mechanical contrivances.

Ir may perhaps appear, at first, to be a farther confequence of the principles I have been endeavouring to establish, that the difficulty of philofophical discoveries 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 suppose, on a fuperficial view of the fubject. To employ, with skill, the very delicate inftrument which nature has made effentially subfervient to general reasoning, and to guard against the errors which result from an injudicious use 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 science of far more extensive 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, must for ever remain in its infancy, till a moft difficult and important defideratum in the hiftory of the mind is fupplied, by an explanation of the gradual steps 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

IV.

CHAP. we are expofed by an incautious ufe of words, I took notice in the preceding Section; and I shall have occafion afterwards to treat the fame 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 rafh 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 study of particulars, and directing his attention to general principles. I flatter myself it appears farther, from the fame reafonings, that it is in confequence of the use 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 address are necessary, both in establishing their truth, and in applying them to practice. Without a proper attention to the circumstances by which their application to particular cafes must be modified, they will be

2

a per

IV.

a perpetual fource of mistake, and of disappointment, in the CHA P. conduct of affairs, however rigidly just they may be in themfelves, and however accurately we may reason from them. If our general principles happen to be falfe, they will involve us in errors, not only of conduct but of fpeculation; and our errors will be the more numerous, the more comprehenfive the principles are on which we proceed.

To illuftrate these observations fully, would lead to a minuteness of difquifition inconsistent with my general plan; and I shall therefore, at present, confine myself to such remarks as appear to be of moft 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 neceffary 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 these 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 scarcely have thought of ftating them in this Chapter, if fome of the most celebrated philofophers of antiquity had not

been

IV.

CHA P. 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 diftinguishing qualities of objects, and giving a common name to their resembling qualities, they conceived univerfals to be real existences, or (as they expreffed it) to be the effences of individuals; and flattered themfelves with the belief, that by directing their attention to these effences in the firft inftance, they might be enabled to penetrate the fecrets of the universe, without fubmitting to the ftudy of nature in detail. These errors, which were common to the Platonifts and the Peripatetics, and which both of them feem to have adopted from the Pythagorean fchool, contributed, perhaps more than any thing else, to retard the progress of the ancients in physical knowledge. The late learned Mr. Harris is almoft the only author of the present age who has ventured to defend this plan of philofophifing, in oppofition to that which has been fo fuccefsfully followed by the difciples of lord Bacon.

"THE Platonists," fays he, " confidering science as fomething ascertained, definite, and steady, would admit nothing "to be its object which was vague, indefinite, and paffing. "For this reason they excluded all individuals or objects of "fenfe, and (as Ammonius expreffes it) raised themselves in "their contemplations from beings particular to beings uni"verfal, and which, from their own nature, were eternal and "definite."-" Confonant to this was the advice of Plato, with refpect to the progress of our speculations and inquiries, to "defcend

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IV.

"defcend from thofe higher genera, which include many fub- CHAP. "ordinate fpecies, down to the lowest rank of fpecies, thofe "which include only individuals. But here it was his opi "nion, that our enquiries fhould ftop, and, as to individuals, "let them wholly alone; because of these there could not poffibly be any science *"

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"SUCH," continues this author, "was the method of an"cient philofophy. The fashion, at prefent, appears to be "fomewhat altered, and the business of philofophers to be little "elfe, than the collecting from every quarter, into voluminous "records, an infinite number of fenfible, particular, and un"connected facts, the chief effect of which is to excite our "admiration."-In another part of his works the fame author obferves, that "the mind, truly wife, quitting the study of particulars, as knowing their multitude to be infinite and incomprehenfible, turns its intellectual eye to what is general "and comprehenfive, and through generals learns to fee, and recognise whatever exifts +."

If we abftract from thefe obvious errors of the ancient philofophers, with refpect to the proper order to be observed in our inquiries, and only fuppofe them to end where the Platonists faid that they should begin, the magnificent encomiums they bestowed on the utility of those comprehenfive truths which form the object of fcience (making allowance for the obfcure and myfterious terms in which they expreffed them) can scarcely be regarded as extravagant. It is probable that * HARRIS'S Three Treatifes, pages 341, 342. + Ibid. page 227. Ff

from