any objects perceivable by fenfe, yet that they have an existence independent of the human mind, and are no more to be confounded with the understanding, of which they are the proper objects, than material things are to be confounded with our pow ers of external perception: that as all the individuals which compofe a genus, muft poffefs fomething in common; and as it is in confequence of this, that they belong to that genus, and are diftinguishable by the fame name, this common thing forms the ef fence of each; and is the object of the understanding, when we reafon concerning the genus. They maintained alfo, that this common effence, notwithstanding its infeparable union with a multitude of different individuals, is in itself one, and indivifible.

On most of these points, the philofophy of Arif totle feems to have coincided very nearly with that of Plato. The language, however, which thefe phi-lofophers employed on this fubject was different, and gave to their doctrines the appearance of a wider diverfity than probably exifted between their opinions. While Plato was led, by his paffion for the marvellous and the mysterious, to infift on the incomprehenfible union of the fame idea or effence, with a number of individuals, without multiplication or divifion;t Aristotle, more cautious, and aiming at

* In this very imperfect sketch of the opinions of the ancients concerning universals, I have substituted, instead of the word idea, the ord essence, as better fitted to convey to a modern reader the true import of Plato's expressions. The word essentia is said to have been first employed by Cicero; and it was afterwards adopted by the schoolmen, in the same sense in which the Platonists used the word idea. See Dr. Reid's Essays on the Intellectual Powers, page

473.

"The idea of a thing." (says Plato,)" is that which makes one of the which, preserving the unity and integrity of its own nature, runs through and mixes with things infinite in

many:

greater perfpicuity, contented himself with faying, that all individuals are compofed of matter and form; and that it is in confequence of poffeffing a common form, that different individuals belong to the fame genus. But they both agreed, that, as the matter, or the individual natures of objects were perceived by fenfe; fo the general idea, or effence, or form, was perceived by the intellect; and that, as the attention of the vulgar was chiefly engroffed with the former, fo the latter furnifhed to the philofopher the materials of his fpeculations.

The chief difference between the opinions of Plato and Ariftotle on the subject of ideas, related to the mode of their exiftence. That the matter of which all things are made, existed from eternity, was a principle which both admitted; but Plato farther taught, that, of every fpecies of things, there is an idea or form which also exifted from eternity; and that this idea is the exemplar or model according to which the individuals of the fpecies were made; whereas Ariftotle held, that, although matter' may exift without form, yet that forms could not exift without matter.*

"number; and yet, however multiform it may appear, is always "the same so that by it we find out and discriminate the thing, "whatever shapes it may assume, and under whatever disguise it I may conceal itself."-PLATO in PHILEBO; (quoted by the Author of the Origin and progress of Language, vol. i. p. 100, 2d edit.)

In this account of the difference between Plato and Aristotle on the subject of ideas, I have chiefly followed Brucker, whose very laborious researches with respect to this article of the history of philosophy are well known. In stating the distinction, however, I have confined myself to as general terms as possible; as the subject is involved in much obscurity, and has divided the opinions of very eminent writers. The reader will find the result of Brucker's inquiries, in his own words, in Note [F.]

The authority of Brucker, in this instance, has the more weight

The doctrine of the Stoics concerning univerfals, differed widely from those both of Plato and Aristotle, and feems to have approached to a fpeculation which is commonly fuppofed to be of a more recent origin, and which an eminent philofopher of the prefent age has ranked among the difcoveries which do the greatest honour to modern genius.*

Whether this doctrine of the Stoics coincided entirely with that of the Nominalifts, (whofe opinions I fhall afterwards endeavour to explain,) or whether it did not resemble more, a doctrine maintained by another fect of schoolmen called Conceptualifts, I fhall not inquire. The determination of this queftion is interefting only to men of erudition; for the knowl edge we poffefs of this part of the Stoical philofophy, is too imperfect to affift us in the farther profecution of the argument, or even to diminish the merit of thofe philofophers who have, in modern times, been led to fimilar conclufions.t

with me, as it coincides in the most material respects with that of Dr. Reid. See his Essays on the Intellectual Powers of Man, and the conclusion of his Inquiry into the Human mind.

A very different account of Aristotle's doctrine, in those particu lars in which it is commonly supposed to differ from that of Plato, is given by two modern writers of great learning, whose opinions are justly entitled to much respect, from their familiar acquaintance with Aristotle's latter Commentators of the Alexandrian School. -See Origin and Progress of Language, vol. i. and HARRIS'S Herines.

It is of no consequence, for any of the purposes which I have at present in view, what opinion we form on this much controverted point of philosophical history. In so far as the ideal theory was an attempt to explain the manner in which our general speculations are carried on, it is agreed on all hands, that the doctrines of Plato and Aristotle were essentially the same; and accordingly, what I have said on that subject, coincides entirely with a passage which the reader will find in " Origin and Progress of Language," vol. i. p. 38. 2d edit.

*Treatise of Human Nature, book i. part i. sect. 7.

+ See Note [G.]

As it is not my object, in this work, to enter into historical details, any farther than is neceffary for illuftrating the subjects of which I treat, I fhall pafs over the various attempts which were made by the Eclectic philofophers, (a fect which arose at Alexandria about the beginning of the third century,) to reconcile the doctrines of Plato and Ariftotle concerning ideas. The endlefs difficulties, it would appear, to which their speculations led, induced, at last, the more cautious and modeft inquiries to banish them entirely from Dialectics, and to content themfelves with studying the arrangements or claffifications of univerfals, which the antient philofophers had made, without engaging in any metaphyfical difquifitions concerning their nature. Porphyry, in particular, although he tells us, that he had speculated much on this fubject; yet, in his Introduction to Ariftotle's Categories, waves the confideration of it as obfcure and intricate. On fuch queftions as thefe; "Whether genera and fpecies exift in nature, 66 or are only conceptions of the Human Mind; and "(on the fuppofition that they exist in nature) "whether they are inherent in the objects of sense, "or disjoined from them?" he declines giving any

determination.

This paffage in Porphyry's Introduction is an object of curiofity; as, by a fingular concurrence of circumftances, it ferved to perpetuate the memory of a controverfy from which it was the author's intention to divert the inquiries of his readers. Amidft ́the disorders produced by the irruptions of the Barbarians, the knowledge of the Greek tongue was almoft entirely loft; and the ftudies of philofophers were confined to Latin verfions of Ariftotle's Dialectics, and of Porphyry's Introduction concerning the Categories. With men who had a relifh for fuch difquifitions, it is probable that the paffage already quoted from Porphyry, would have a tendency rath

er to excite than to damp curiofity; and according ly, we have reafon to believe, that the controverfy to which it relates continued, during the dark ages to form a favourite fubject of difcuffion. The opinlon which was prevaient was, (to use the fcholaftic language of the times,) that univerfals do not exist before things, nor after things, but in things; that is, (if I may be allowed to attempt a commentary upon expreffions to which I do not pretend to be able to annex very precise notions,) univerfal ideas have not (as Plato thought) an existence feparable from individual objects; and, therefore, they could not have exifted prior to them in the order of time; nor yet, (according to the doctrine of the Stoics,) are they mere conceptions of the mind, formed in confequence of an examination and comparison of particulars; but these ideas or forms are from eternity united infeparably with that matter of which things confift; or, as the Ariftotelians fometimes exprefs themselves, the forms of things are from eternity immerfed in matter. The reader will, I hope, forgive me for entering into these details, not only on account of their connection with the obfervations which are to follow; but as they relate to a controverfy which, for many ages, employed all the ingenuity and learning in Europe; and which, therefore, however frivolous in itfelt, deferves the attention of philofophers, as one of the most curious events which occurs in the hiftory of the Human Mind.

Such appears to have been the prevailing opinion concerning the nature of univerfals, till the eleventh century; when a new doctrine, or (as fome authors think) a doctrine borrowed from the school of Zeno, was proposed by Rofcelinus ;* and foon after very widely propagated over Europe by the abilities and eloquence of one of his scholars, the celebrated Peter

See Note [H.]