house, where they are to be used. This repository I conceive to be seated in the brain; and the substance thereof I conceive to be the material out of which these ideas are formed, and where they are also preserved, when formed, being disposed in some regular order; which order I conceive to be principally that according to which they are formed; that being first in order that is first formed, and that next which is next; and so on continually by succession, from the time of our birth to the time of our death. So that there is, as it were, a continued chain of ideas coiled up in the repository of the brain, the first end of which is farthest removed from the centre, or seat of the soul, where the ideas are formed, and the other end is always at the centre, being the last idea formed, which is always the moment present when considered. And therefore, according as there are a greater number of these ideas between the present sensation or thought in the centre, and any other, the more is the soul apprehensive of the time interposed."

To those who are acquainted with the strong bent of Hooke's genius toward mechanics, and who recollect, that, from his childhood, the art of watch-making was one of his favorite studies,* it may be amusing to combine, with the foregoing extract, a remark which occurs more than once in the works of Lord Bacon: "When men of confined scientific pursuits afterwards betake themselves to philosophy, and to general contemplations, they are apt to wrest and corrupt them with their former conceits."-Nor is Hooke the only writer of note, since Bacon's time, who has exemplified the truth of this maxim. Another illustration of it, still more closely connected with the subject of this Essay, occurs in a profound mathematical work (entitled Harmonics) by Dr. Smith of Cambridge. I shall quote the passage I allude to, in the author's words, as it contains (independently of its reference to my present purpose) a curious hint towards a physiological theory of the mind, founded on the very same hypothesis which

* See the Account of his Life.

was afterwards adopted by Hartley." With a view to some other inquiries, I will conclude with the following observations: That, as almost all sorts of substances are perpetually subject to very minute vibratory motions, and all our senses and faculties seem chiefly to depend upon such motions excited in the proper organs, either by outward objects, or the powers of the will, there is reason to expect, that the theory of vibra tions here given, will not prove useless in promoting the philosophy of other things besides musical sounds." *

Among modern philosophers, however, I am acquainted with none to whom Bacon's aphorism applies with nearly so great force, as to the ingenious physician whose hypothesis, concerning the materiality of ideas, has led me insensibly into these reflections. The influence of his medical occupations on his habits of thinking, may be traced in almost every page of his works, both philosophical and poetical ;-not only in the physiological language in which he uniformly describes our mental operations, but even in his detached theories upon the various incidental questions which he has started. It is sufficient for me to mention, as instances, his account of the mechanical process by which the human countenance is first moulded into a smile;-and his theory of beautiful forms, deduced from the pleasurable sensations, associated by an infant with the bosom of its nurse. The enthusiastic praise which he bestows on a conjecture of Mr. Hume's, that "the world may possibly have been generated rather than created," † is perhaps explicable, in part, on the same principle.

The propensity which all men have to explain the intellectual phenomena, by analogies borrowed from the material world, has its origin in an error, differing from that which misled Hooke and Darwin, only in this, that the latter, being the natural result of the favorite, or of the professional habits of the individual, assumes as many different shapes as the pursuits of mankind; whereas the former, having its root in the common principles and common circumstances of the human race,

* See Harmonics, printed at Cambridge in 1749. The Preface is dated in 1748. † See Zoonomia, Vol. II. p. 247, 3d edit.

may be expected to exert its influence on the theories of philosophers, in every country, and in every age. The one prejudice would have been classed by Bacon with the idola specûs; the other, with the idola tribús. But I must not enlarge farther on systems which, whatever may have been the views of their authors, have obviously no logical connexion with the problem relating to the sources of our ideas; a problem which (as I have repeatedly observed) is to be solved, not by any hypothesis concerning the nature of mind, but by an appeal to the phenomena of thought, and by an accurate analysis of the objects of our knowledge.—On these grounds, our attention is naturally attracted to a new and very interesting class of facts, which have been accumulated, of late, with extraordinary industry, as an inductive demonstration of the justness of those principles which I have been endeavouring to controvert; and which have been recommended to public notice, (in one instance, at least,) by a much more splendid display of learning and genius, than has been yet exhibited by any of our metaphysical physiologists. I allude to the philological researches of Mr. Horne Tooke.

Before, however, I enter upon any discussions concerning the inferences which these researches have been supposed to authorize, it is necessary for me to take a pretty wide compass, by premising some general observations; the scope of which I am afraid it may be difficult for my readers, at first view, to connect with the inquiries in which we have been hitherto engaged. I shall state, therefore, the whole of my argument at once, as clearly and fully as I can, in a separate Essay.

ESSAY FIFTH.

ON THE TENDENCY OF SOME LATE PHILOLOGICAL SPECULATIONS.

CHAPTER FIRST.

IN carrying back our thoughts to the infancy of a cultivated language, a difficulty occurs, which, however obviously it may seem to present itself, I do not recollect to have seen taken notice of by any writer on the human mind; and which, as it leads the attention to various questions closely connected with the main design of this volume, as well as with the particular discussion which has been last under our review, I shall point out and illustrate at some length.

In the case of objects which fall under the cognizance of any of our external senses, it is easy to conceive the origin of the different classes of words composing a conventional dialect; to conceive, for example, that two savages should agree to call this animal a Horse, and that tree an Oak. But, in words relating to things intellectual and moral, in what manner was the conventional connexion at first established between the sign and the thing signified? In what manner (to take one of the simplest instances) was it settled, that the name of imagination should be given to one operation of the mind; that of recollection to a second; that of deliberation to a third; that of sagacity, or foresight, to a fourth? Or, supposing the use of these words to be once introduced, how was their meaning to be explained to a novice, altogether unaccustomed to think upon such subjects?

1. In answer to this question, it is to be observed, in the first place, that the meaning of many words, of which it is impossible to exhibit any sensible prototypes, is gradually collected by a species of induction, which

is more or less successfully conducted by different individuals, according to the degree of their attention. and judgment. The connexion in which an unknown term stands in relation to the other words combined with it in the same sentence, often affords a key for its explanation in that particular instance; and in proportion as such instances are multiplied in the writings and conversation of men well acquainted with propriety of speech, the means are afforded of a progressive approximation towards its precise import. A familiar illustration of this process presents itself in the expedient which a reader naturally employs for deciphering the meaning of an unknown word in a foreign language, when he happens not to have a dictionary at hand. The first

sentence where the word occurs, affords, it is probable, sufficient foundation for a vague conjecture concerning the notion annexed to it by the author;-some idea or other being necessarily substituted in its place, in order to make the passage at all intelligible. The next sentence where it is involved, renders this conjecture a little more definite; a third sentence contracts the field of doubt within still narrower limits; till, at length, a more extensive iuduction fixes completely the signification we are in quest of. There cannot be a doubt, I apprehend, that it is in some such way as this, that children slowly and imperceptibly enter into the abstract and complex notions annexed to numberless words in their mother tongue, of which we should find it difficult or impossible to convey the sense by formal definitions.*

2. The strong tendency of the mind to express itself metaphorically, or analogically, on all abstract subjects, supplies another help to facilitate the acquisition of language. The prevalence of this tendency among rude nations has been often remarked; and has been commonly accounted for, partly from the warmth of imagination supposed to be peculiarly characteristical of savages, and partly from the imperfections of their scanty

Hence the logical utility of metaphysical pursuits in training the mind to these inductive processes, so essentially connected with precision in the use of language, and, of consequence, with accuracy of reasoning, in all the various employments of the intellectual powers.