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This difference in point of degree (it must at the same time be remembered) leads, where it is great, to important consequences. In proportion as the resemblance between two cases diminishes in the palpable marks which they exhibit to our senses, our inferences from the one to the other are made with less and less confidence; and therefore it is perfectly right, that we should reason with more caution from species to species, than from individual to individual of the same kind. In what follows, accordingly, I shall avail myself of the received distinction between the words experience and analogy; a distinction which I have hitherto endeavoured to keep out of view, till I should have an opportunity of explaining the precise notion which I annex to it. It would, in truth, be a distinction of important use in our reasonings, if the common arrangements, instead of originating, as they have often done, in ignorance or caprice, had been really the result of an accurate observation and comparison of particulars. With all the imperfections of these arrangements, however, a judicious inquirer will pay so much regard to prevailing habits of thinking, as to distinguish very scrupulously what common language refers to experience from what it refers to analogy, till he has satisfied himself, by a diligent examination, that the distinction has, in the instance before him, no foundation in truth. On the other hand, as mankind are much more disposed to confound things which ought to be distinguished, than to distinguish things which are exactly or nearly similar, he will be doubly

tions, on verra que nous n'avons fait autre chose que leur donner de la précision." (Essais de Philosophie, Tome I. p. 202.)

See also the remarks on induction and analogy in the four following articles of M. Prévost's work.

cautious in concluding, that all the knowledge which common language ascribes to experience is equally solid; or that all the conjectures which it places to the account of analogy are equally suspicious.

A different idea of the nature of analogy has been given by some writers of note; and it cannot be denied, that, in certain instances, it seems to apply still better than that proposed above. The two accounts, however, if accurately analyzed, would be found to approach much more nearly, than they appear to do at first sight; or rather, I am inclined to think, that the one might be resolved into the other, without much straining or over-refinement. But this is a question chiefly of speculative curiosity, as the general remarks which I have now to offer, will be found to hold with respect to analogy, considered as a ground of philosophical reasoning, in whatever manner the word is defined; provided only it be understood to express some sort of correspondence or affinity between two subjects, which serves, as a principle of association or of arrangement, to unite them together in the mind.

According to Dr. Johnson, (to whose definition I allude more particularly at present) analogy properly means "a resemblance between things with regard to some circumstances or effects; as when learning is said to enlighten the mind; that is, to be to the mind what light is to the eye, by enabling it to discover that which was hidden before." The statement is expressed with a precision and justness not always to be found in the definitions of this author; and it agrees very nearly with the notion of analogy adopted by Dr. Ferguson, that "things which have no resemblance to each other may nevertheless be

analogous; analogy consisting in a resemblance or correspondence of relations."* As an illustration of this, Dr. Ferguson mentions the analogy between the fin of a fish and the wing of a bird; the fin bearing the same rela tion to the water, which the wing does to the air. This definition is more particularly luminous, when applied to the analogies which are the foundation of the rhetorical figures of metaphor and allusion; and it applies also very happily to those which the fancy delights to trace between the material and the intellectual worlds; and which (as I have repeatedly observed,) are so apt to warp the judgment in speculating concerning the phenomena of the human mind.

The pleasure which the fancy receives from the contemplation of such correspondences, real or supposed, obviously presupposes a certain disparity or contrast in the natures of the two subjects compared; and, therefore, analogy forms an associating principle, specifically different from resemblance, into which Mr. Hume's theory would lead us to resolve it. An additional proof of this is furnished by the following consideration, That a resemblance of objects or events is perceived by sense, and accordingly has some effect even on the lower animals; a correspondence (or, as it is frequently called, a resemblance) of relations, is not the object of sense, but of intellect, and consequently, the perception of it implies the exercise of

reason.

Notwithstanding, however, the radical distinction between the notions expressed by the words resemblance

* Principles of Moral and Political Science. Vol. I. p. 107.

and analogy, they may often approach very nearly to each other in their meaning: and cases may even be conceived, in which they exactly agree. In proof of this, it is sufficient to remark, that in objects, the parts of which respectively exhibit that correspondence which is usually distinguished by the epithet analogous, this correspondence always deviates, less or more, from an exact conformity or identity; insomuch, that it sometimes requires a good deal of consideration to trace in detail the parallel circumstances, under the disguises which they borrow from their diversified combinations. An obvious instance of this occurs when we attempt to compare the bones and joints in the leg and foot of a man with those in the leg and foot of a horse. Were the correspondence in all the relations perfectly exact, the resemblance between the two objects would be manifest even to sense; in the very same manner that, in geometry, the similitude of two triangles is a necessary consequence of a precise correspondence in the relations of their homologous sides.”*

This last observation may serve, in some measure, to justify an assertion which was already hazarded,—That the two definitions of analogy formerly mentioned, are very nearly allied to each other ;-inasmuch as it shows, by a more careful analysis than has commonly been applied to this subject, that the sensible dissimilitude between things of different species arises chiefly from the want of a palpable conformity in the relations of their constituent parts. Conceive that more remote correspondence which reason or fancy traces between the parts of the one and the parts of the other, gradually to approach

* See Note (Q.)

nearer and nearer to the same standard; and it is evident, that, in the course of the approximation, you will arrive at that degree of manifest resemblance, which will bring them under the same generic name; till at last, by continuing this process of the imagination, the one will become a correct picture or image of the other, not only in its great outlines, but in its minutest details.

From this view of the subject, too, as well as from the former, it appears, how vague and ill defined the metaphysical limits are which separate the evidence of analogy from that of experience; and how much room is left for the operation of good sense, and of habits of scientific research, in appreciating the justness of that authority which, in particular instances, the popular forms of speech may assign to either.

The illustrations which I have to offer of this last remark, in so far as it relates to experience, may, I think, be introduced more usefully afterwards; but the vague conceptions which are generally annexed to the word analogy, together with the prevailing prejudices against it, as a ground of philosophic reasoning, render it proper for me, before proceeding any farther, to attempt the correction of some popular mistakes connected with the use of this obnoxious term.

It is not necessary, for the purposes which I have at present in view, to investigate very curiously the principles which, in the first instance, dispose the mind to indulge in analogical conjectures from the known to the unknown. It is sufficient to observe, that this disposition, so far from being checked, receives additional encourage

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