existence. With refpect to the fubferviency of this faculty to poetical imagination, it is no lefs obvious, that, as the poet is fupplied with all his materials by experience; and as his province is limited to combine and modify things which really exift, so as to produce new wholes of his own; fo every exertion which he thus makes of his powers, presupposes the exercise of abstraction in decompofing and feparating actual combinations. And it was on this account that, in the chapter on Conception, I was led to make a diftinction between that faculty, which is evidently fimple and uncompounded, and the power of Imagination, which (at least in the fenfe in which I employ the word in these inquiries) is the result of a combination of various other powers.

I have introduced these remarks, in order to point out a difference between the abstractions which are fubfervient to reafoning, and those which are subser. vient to imagination. And, if I am not mistaken, it is a diftinction which has not been fufficiently attended to by fome writers of eminence. In every instance in which imagination is employed in forming new wholes, by decompounding and combining the perceptions of fenfe, it is evidently neceffary that the poet or the painter fhould be able to ftate to himself the circumstances abstracted, as feparate objects of conception. But this is by no means requifite in every cafe in which abftraction is fubfervient to the power of reafoning; for it frequently happens, that we can reafon con. cerning one quality or property of an object abftracted from the rest, while, at the fame time, we find it impoffible to conceive it feparately. Thus, I can rea

fon

fon concerning extenfion and figure, without any reference to colour; although it may be doubted, if a perfon poffeffed of fight can make extenfion and figure fteady objects of conception, without connecting with them one colour or another. Nor is this always owing (as it is in the inftance now mentioned) merely to the affociation of ideas; for there are cafes, in which we can reafon concerning things feparately, which it is impoffible for us to fuppofe any being fo conftituted as to conceive apart. Thus, we can reafon concerning length, abftracted from any other dimenfion; although, furely, no understanding can make length, without breadth, an object of conception. And, by the way, this leads me to take notice of an error, which mathematical teachers are apt to commit, in explaining the first principles of geometry. By dwelling long on Euclid's first definitions, they lead the student to fuppofe that they relate to notions which are extremely myfterious; and to strain his powers in fruitlefs attempts to conceive, what cannot poffibly be made an object of conception. If these definitions were omitted, or very flightly touched upon, and the attention at once directed to geometrical reafonings, the ftudent would immediately perceive, that although the lines in the diagrams are really extended in two dimenfions, yet that the demonstrations relate only to one of them; and that the human understanding has the faculty of reasoning concerning things feparately, which are always prefented to us, both by our powers of perception and conception, in a state of union. Such abstractions, in truth, are familiar to the moft illiterate of mankind

and

and it is in this very way that they are infenfibly formed. When a tradesman speaks of the length of a room, in contradiftinction to its breadth; or when he speaks of the distance between any two objects; he forms exactly the fame abftraction, which is referred to by Euclid in his fecond definition; and which most of his commentators have thought it neceffary to illuftrate by prolix metaphyfical difquifi

tions.

I fhall only obferve farther, with refpect to the nature and province of this faculty of the mind, that notwithstanding its effential fubferviency to every act of claffification, yet it might have been exercifed, although we had only been acquainted with one individual object. Although, for example, we had never seen but one rofe, we might still have been able to attend to its colour, without thinking of its other properties. This has led fome philofophers to fuppose, that another faculty befides abftraction, to which they have given the name of generalifation, is neceffary to account for the formation of genera and fpecies; and they have endeavoured to fhew, that although generalisation without abftraction is impoffible; yet that we might have been fo formed, as to be able to abstract, without being capable of generalifing. The grounds of this opinion, it is not neceffary for me to examine, for any of the purposes which I have at prefent in view.

SECTION

SECTION II.

Of the Objects of our Thoughts, when we employ general Terms.

FROM the account which was given in a former

it

chapter, of the common theories of perception, appears to have been a prevailing opinion among philofophers, that the qualities of external objects are perceived, by means of images or fpecies tranfmitted to the mind by the organs of fense: an opinion of which I already endeavoured to trace the origin, from certain natural prejudices fuggefted by the phenomena of the material world. The fame train of thinking has led them to fuppofe that, in the cafe of all our other intellectual operations, there exift in the mind certain ideas distinct from the mind itself; and that these ideas are the objects about which our thoughts are employed. When I recollect, for example, the appearance of an abfent friend, it is fuppofed that the immediate object of my thoughts is an idea of my friend; which I at first received by my fenfes, and which I have been enabled to retain in the mind by the faculty of memory. When I form to myself any imaginary combination by an effort of poetical invention, it is fuppofed, in like manner, that the parts which I combine, exifted previoufly in the mind; and furnish the materials on which it is the province of imagination to operate. It is to Dr. Reid we owe the important remark, that all thefe notions are wholly hypothetical; that it is impoffible to produce a fhadow

8

a fhadow of evidence in fupport of them; and that, even although we were to admit their truth, they would not render the phenomena in question more intelligible. According to his principles, therefore, we have no ground for fuppofing, that, in any one operation of the mind, there exists in it an object diftinct from the mind itself; and all the common expreffions which involve fuch a fuppofition, are to be confidered as unmeaning circumlocutions, which ferve only to disguise from us the real hiftory of the intellectual phenomena *.

"We

* In order to prevent misapprehenfions of Dr. Reid's meaning, in his reafonings against the ideal theory, it may be neceffary to explain, a little more fully than I have done in the text, in what fense he calls in queftion the existence of ideas: for the meaning which this word is employed to convey in popular discourse, differs widely from that which is annexed to it by the philofophers whose opinion he controverts. This explanation I fhall give in his own words:

"In popular language, idea fignifies the fame thing as concep "tion, apprehenfion, notion. To have an idea of any thing, is "to conceive it. To have a diftinct idea, is to conceive it dif "tinctly. To have no idea of it, is not to conceive it at all.— "When the word idea is taken in this popular fenfe, no man can "poffibly doubt whether he has ideas.”

"According to the philofophical meaning of the word idea, it ❝ does not fignify that act of the mind which we call thought, or "conception, but fome object of thought. Of these objects of "thought called ideas, different fects of philofophers have given very different accounts."

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"Some have held them to be self-existent; others to be in the "divine mind; others in our own minds; and others in the brain, " or fenforium." p. 213.

"The Peripatetick fyftem of species and phantafms, as well as "the Platonick fyftem of ideas, is grounded upon this principle,

M

* that