which has often struck me in contrasting the views of the Alchemists with those of Lavoisier and his followers, has acquired much additional value and importance in my estimation, since I had the pleasure to peruse a late work of M. De Gerando; in which I find, that the same analogy has presented itself to that most judicious philosopher, and has been applied by him to the same practical purpose, of exposing the false pretensions and premature generalizations of some modern metaphysicians.

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"It required nothing less than the united splendour of the discoveries brought to light by the new chemical school, to tear the minds of men "from the pursuit of a simple and primary ele"ment; a pursuit renewed in every age with an indefatigable perseverance, and always renewed in "vain. With what feelings of contempt would the physiologists of former times have looked down on the chemists of the present age, whose timid "and circumscribed system admits nearly forty dif"ferent principles in the composition of bodies! "What a subject of ridicule would the new nomen"clature have afforded to an Alchemist!"

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"The Philosophy of Mind has its Alchemists al"so ;-men whose studies are directed to the pur"suit of one single principle, into which the whole "science may be resolved; and who flatter them"selves with the hope of discovering the grand se

cret, by which the pure gold of Truth may be "produced at pleasure."

* De Gerando, Hist. des Systêmes, Tom. II. pp. 481, 482.

Among these Alchemists in the science of Mind, the first place is undoubtedly due to Dr Hartley, who not only attempts to account for all the phenomena of human nature, from the single principle of Association, combined with the hypothetical assumption of an invisible fluid or ether, producing Vibrations in the medullary substance of the brain and nerves; but indulges his imagination in antieipating an æra, "when future generations shall

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put all kinds of evidences and inquiries into ma"thematical forms; reducing Aristotle's ten catego"ries, and Bishop Wilkins' forty summa genera, "to the head of Quantity alone, so as to make ma"thematics and logic, natural history and civil his"tory, natural philosophy, and philosophy of all "other kinds, coincide omni ex parte." If I had never read another sentence of this author, I should have required no farther evidence of the unsoundness of his understanding.

It is, however, on such rash and unwarranted assertions as this, combined with the supposed comprehensiveness of his metaphysical views, that the peculiar merits of Hartley seem now to be chiefly rested by the more enlightened of his admirers. Most of these, at least whom I have happened to converse with, have spoken of his physiological doctrines as but of little value, compared with the wonders which he has accomplished by a skilful use of the Associating Principle. On this head, therefore, I must request the attention of my readers to a few, short remarks.

III. Of the most celebrated theorists who have

nomena.

appeared since the time of Lord Bacon, by far the greater part have attempted to attract notice, by displaying their ingenuity in deducing, from some general principle or law, already acknowledged by philosophers, an immense variety of particular pheFor this purpose, they have frequently found themselves under the necessity of giving a false gloss to facts, and sometimes of totally misrepresenting them; a practice which has certainly contributed much to retard the progress of experimental knowledge; but which, at the same time, must be allowed (at least in Physics) to have, in some cases, prepared the way for sounder conclusions. The plan adopted by Hartley is very different from this, and incomparably more easy in the execution. The generalizations which he has attempted are merely verbal; deriving whatever speciousness they may possess, from the unprecedented latitude given to the meaning of common terms. After telling us, for example, that "all our inter"nal feelings, excepting our sensations, may be "called ideas ;" and giving to the word Association a corresponding vagueness in its import, he seems to have flattered himself, that he had resolved into one single law, all the various phenomena, both intellectual and moral, of the Human Mind. What advantage, either theoretical or practical, do we reap from this pretended discovery ;-a discovery necessarily involved in the arbitrary definitions with which the author sets out? I must acknowledge, that I can perceive none-while, on the other hand, its effect must clearly be, by perverting or

dinary language, to retard the progress of a science, which depends, more than any other, for its improvement, on the use of precise and definite expressions. *

With respect to the phrase association of ideas, which makes such a figure, not only in Hartley, but in most of the metaphysical writers whom England has since produced, I shall take this opportunity to remark, how very widely its present acceptation differs from that invariably annexed to it in Locke's Essay. In his short chapter on this subject (one of the most valuable in the whole work), his observations relate entirely to "those connections of ideas "that are owing to chance; in consequence of which "connections, ideas that, in themselves, are not at "all a-kin, come to be so united in some men's “ minds, that it is very hard to separate them; and "the one no sooner, at any time, comes into the

* Under the title of Association, Hartley includes every connection which can possibly exist among our thoughts; whether the result of our natural constitution, or the effect of accidental circumstances, or the legitimate offspring of our rational powers, Even our assent to the proposition, that twice two is four, is (according to him) only a particular case of the same general law. "The cause that a person affirms the truth of the proposition, twice two is four, is the entire coincidence of the visible or tangible idea of twice two with that of four, as impressed upon the mind by various objects. We see everywhere, that twice two and four are only different names for the same impression. And it is mere association which appropriates the word truth, its definition, or its internal feeling, to this coincidence."-Hartley on Man, Vol. I. p. 325. 4th edit.

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"understanding, but its Associate appears with it." His reason for dwelling on these, he tells us expressly, is, "that those who have children, or the charge of "their education, may think it worth their while dili"gently to watch, and carefully to prevent the undue "connection of ideas in the minds of young people. "This," he adds, "is the time most susceptible of last"ing impressions; and though those relating to the "health of the body are, by discreet people, minded "and fenced against; yet I am apt to doubt, that "those which relate more peculiarly to the mind, and "terminate in the understanding, or passions, have "been much less heeded than the thing deserves;

nay, those relating purely to the understanding "have, as I suspect, been by most men wholly over"looked."

From these quotations, it is evident that Mr Locke meant to comprehend, under the association of ideas, those Associations alone, which, for the sake of distinction, I have characterized, in my former work, by the epithet casual. To such as arise out of the nature and condition of man (and which, in the following Essays, I generally denominate universal Associations), Mr Locke gives the title of Natural Connections; observing, with regard to them, that "it is the office and excellency of reason "to trace them, and to hold them together in "union." If his language on this head had been more closely imitated by his successors, many of the errors and false refinements into which they have fallen, would have been avoided. Mr Hume was one of the first who deviated from it, by the enlarg◄