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inftant, are situated within the sphere of their activity, and no sooner discharge their office in any particular ivstance, than the articles of inforniation exhibited by them, are devolved on the memory. Remembrance instantly succeeds senlation, insomuch that the memory becomes the sole repository of the knowledge received from sense ; knowledge which, without this repofitory, would be as instantaneously loft as it is gotten, and could be of no service to the mind. Our sensations would be no better than the fleeting pictures of a moving object on a cainera obicura, which leave not the least veftige behind them. Memory therefore is the only original voucher extant, of thofe past realities for which we had once the evidence of sense. Her ideas are, as it were, the prints that have been left by sensible impreslions. But from these two faculties, considered in themselves, there results to us the knowledge only of individual facts, and only of such facts as either heretofore have come, or at present do come, under the notice of our fenfes.

Now, in order to render this knowledge useful to us, in discovering the nature of things, ani in regulating our conduct, a further proeess or the mind is neceffary, which deserves to

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be carefully attended to, and may be thus illuftrated. I have observed a stone fall to the ground when nothing intervened to impede its motion. This single fact produces little or no effect on the mind beyond a bare remembrance. At another time I observe the fall of a tile, at another of an apple, and so of almost every kind of body in the like situation. Thus

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senses firft, and then my memory, furnish ine with nuinerous examples, which, though different in every other particular, are similar in this, that they present a body moving downwards till obfructed either by the ground or by some intervenient object. Hence my first notion of gravitation. For, with regard to the similar citcumstances of different facts, as by the repetition such circumstances are more deeply imprinted, the mind acquires a habit of retaining them, omitting thofe circumstances peculiar to each, wherein their differences confift. · Hence, if objects of any kind in a particular manner circumItanced, are remembered to have been usually, and ftill more, if uniformly, succeeded by certain particular consequences, the idea of the former in the supposed circumstance introduced into the mind,' immediately associates the idea of the latter; and if the object itself so circumstanced,

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be presented to the senses, the mind instantly anticipates the appearance of the customary consequence. This holds also inversely. The retention and affociation above explained, are called Experience. The anticipation is in effect no other than a particular conclusion from that experience. Here we may remark, by the way, that though memory gives birth to experience, which results from the comparison of facts remembered, the experience or habitual association remains, when the individual facts on which it is founded are all forgotten. I know from an experience, which excludes all doubt, the

power of fire in melting silver, and yet may not be able at present to recollect a particular instance in which I have seen this effect produced, or even in which I have had the fact attested by a credible witness.

SOME will perhaps object, tliat the account now given makes our experimental reasoning look like a fort of mechanisin neceffarily resulting from the very conftitution of the mind. I acknowledge the juftnefs of the remark, but do not think that it ought to be regarded as an objection. It is plain that our reafoning in this way, if you please to call it so, is very early,

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and precedes all reflection on our faculties, and the manner of applying them. Those who attend to the progress of human nature through its different stages, and through childhood in particular, ' will observe, that children make great acquisitions in knowledge from experience, long before they attain the use of speech. The beasts also; in their sphere, improve by experience, which hath in them just the same foundations of fense and memory as in us, and bath, besides, a fimilar influence on their actions. It is precisely in the fame manner, and with the same success, that you might train å dog, of accustom a child, to expect food on your calling to him in one tone of voice, and to dread your resentment, when you use another. The brutes have evidently the rudiments of this species of rationality, which extends as far in them as the immediate purposes of self-preservation require, and which, whether you call it reason or instinct, they both acquire and use in the fame manner as we do. That it reaches no farther in them, seems to arise from an original incapacity of claffing, and (if I may use the expreffion) gea neralising their perceptions ; an exercise which to us very quickly becomes familiar, and is what chiefly fits us for the use of language. Indeed,

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11 the extent of this capacity, as much perhaps as in any thing, lies also the principal natural fuperiority of one man over another,

But that we may be satisfied, that to this kind of reasoning, in its earliest and simpleft form, little or no reflection is necessary, let it be observed, that it is now universally admitted by opticians, that it is not purely from fight, but from fight aided by experience, that we derive our notions of the distance of visible objects from the eye. The sensation, say they, is instantaneously, followed by a conclusion or judgment founded an experience. The point is determined from the different phases of the object, found in former trials, to be connected with different distances, or from the effort that accompanies the different conformations we are obliged to give the organs of fight, in order to obtain a diftinct vision of the object. Now if this be the case, as I think hath been sufficiently eyinced of late, it is manifeft, that this judgment is so truly instantaneous, and so perfectly the result of feeling and association, that the forming of it totally escapes our notice. Perhaps in no period of life will you find a person, that, on the first mention of it, can be easily persuaded, that he

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