from the happieft reafoning, to have alfo determin'd the laws and forces, by which the revolutions of the planets are govern'd and directed. The like has been perform'd with regard to other parts of nature. And there is no reason to defpair of equal fuccefs in our enquiries concerning the mental powers and oeconomy, if profecuted with equal capacity and caution. 'Tis probable, that one operation and principle of the mind depends on another; which, again, may be refolv'd into one more general and universal : And how far these researches may poffibly be carry'd, 'twill be difficult for us, before, or even after, a careful trial, exactly to determine. This is certain, that attempts of this kind are every day made even by those who philofophize the most negligently; and nothing can be more requifite than to enter upon the enterprize with thorough care and attention that, if it lie within the compass of human understanding, it may at last be happily atchiev'd; if not, it may, however, be rejected with fome confidence and fecurity. This laft conclufion, furely, is not defirable, nor ought it to be embrac'd too rafhly. For how much must we diminish from the beauty and value of this fpecies of philofophy, upon fuch a fuppofition? Moralifts have hitherto been accuftom'd, when they confider'd the vaft multitude and diverfity of actions that excite our approbation or dislike, to fearch for fome common principle, on which this va

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riety of fentiments might depend. And tho' they have fometimes carry'd the matter too far, by their paffion for fome one general principle; it must, however, be confeft, that they are excufable, in expecting to find some general principles, into which all the vices and virtues were juftly to be refolv'd. The like has been the endeavour of critics, logicians, and even politicians: Nor have their attempts been altogether unfuccefsful; tho' perhaps longer time, greater accuracy, and more ardent application may bring thefe fciences ftill' nearer their perfection. To throw up at once all pretenfions of this kind may justly be efteem'd more rafh, precipitate, and dogmatical, than even the boldest and most affirmative philofophy, which has ever attempted to impose its crude dictates and principles on mankind.

On

WHAT tho' thefe reafonings concerning human nature feem abftract, and of difficult comprehenfion? This affords no prefumption of their falfhood. the contrary, it seems impoffible, that what has hitherto escap'd fo many wife and profound philofophers can be very obvious and easy. And whatever pains these researches may coft us, we may think ourfelves fufficiently rewarded, not only in point of profit but of pleasure, if, by that means, we can make any addition to our stock of knowlege, in fubjects of fuch unspeakable importance.

BUT

Bur as, after all, the abstractness of these speculations is no recommendation, but rather a disadvantage to them, and as this difficulty may perhaps be furmounted by care and ait, and the avoiding all unneceffary detail, we have, in the following effays, attempted to throw fome light upon fubjects, from which uncertainty has hitherto deter'd the wife, and obfcurity the ignorant. Happy, if we can unite the boundaries of the different fpecies of philofophy, by reconciling profound enquiry with clearness, and truth with novelty! And ftill more happy, if, reafoning in this easy manner, we can undermine the foundations of an abftrufe philofophy, which feems to have ferv'd hitherto only as a shelter to fuperftition and a cover to abfurdity and error !

SAY

ESSAY II.

Of the ORIGIN of IDEAS.

EVERY one will readily allow, that there is a

confiderable difference betwixt the perceptions of the mind, when a man feels the pain of exceffive heat, or the pleasure of moderate warmth, and when he afterwards recalls to his memory this sensation, or anticipates it by his imagination. These faculties may mimic or copy the perceptions of the fenfes; but they never can reach entirely the force and vivacity of the original fentiment. The utmost we say of them, even when they operate with greatest vigour, is, that they represent their object in so lively a manner, that we could almost say we feel or fee it: But except the mind be disorder'd by disease or madness, they never can arrive at such a pitch of vivacity as to render these perceptions altogether undistinguishable. All the colours of poetry, however splendid, can never paint natural objects in such a manner as to make the description to be taken for a real landskip. The

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