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inftant, are fituated within the sphere of their activity, and no fooner discharge their office in any particular inftance, than the articles of information exhibited by them, are devolved on the memory. Remembrance inftantly fucceeds fenfation, infomuch that the memory becomes the fole repofitory of the knowledge received from fenfe; knowledge which, without this repofitory, would be as inftantaneously loft as it is gotten, and could be of no fervice to the mind. Our fenfations would be no better than the fleeting pictures of a moving object on a camera obfcura, which leave not the leaft veftige behind them. Memory therefore is the only original voucher extant, of those past realities for which we had once the evidence of fenfe. Her ideas are, as it were, the prints that have been left by fenfible impreffions. But from these two faculties, confidered in themfelves, there refults to us the knowledge only of individual facts, and only of fuch facts as either heretofore have come, or at prefent do come, under the notice of our fenfes.

Now, in order to render this knowledge ufeful to us, in difcovering the nature of things, and in regulating our conduct, a further proeefs of the mind is neceffary, which deferves to

be

be carefully attended to, and may be thus illuftrated. I have obferved a ftone fall to the ground when nothing intervened to impede its motion. This fingle fact produces little or no effect on the mind beyond a bare remembrance. At another time I obferve the fall of a tile, at another of an apple, and fo of almost every kind of body in the like fituation. Thus my fenfes firft, and then my memory, furnish me with numerous examples, which, though different in every other particular, are fimilar in this, that they prefent a body moving downwards till obfructed either by the ground or by fome intervenient object. Hence my first notion of gravitation. For, with regard to the fimilar circumstances of different facts, as by the repetition. fuch circumftances are more deeply imprinted, the mind acquires a habit of retaining them, omitting thofe circumftances peculiar to each, wherein their differences confift. Hence, if objects of any kind in a particular manner circumftanced, are remembered to have been usually, and still more, if uniformly, fucceeded by certain particular confequences, the idea of the former in the fuppofed circumftance introduced into the mind, immediately affociates the idea of the latter; and if the object itself so circumstanced,

be prefented to the fenfes, the mind inftantly anticipates the appearance of the customary confequence. This holds alfo inverfely. The retention and affociation above explained, are called Experience. The anticipation is in effect no other than a particular conclufion from that experience. Here we may remark, by the way, that though memory gives birth to experience, which refults from the comparison of facts remembered, the experience or habitual affociation 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 filver, and yet may not be able at present to recollect a particular inftance in which I have seen this effect produced, or even in which I have had the fact attefted by a credible witnefs.

SOME will perhaps object, that the account now given makes our experimental reasoning look like a fort of mechanifin neceffarily refulting 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 pleafe to call it fo, is very early,

and

and precedes all reflection on our faculties, and the manner of applying them. Those who attend to the progrefs of human nature through its different ftages, and through childhood in particular, will obferve, that children make great acquifitions in knowledge from experience, long before they attain the use of speech. The beafts alfo, in their fphere, improve by experi ence, which hath in them just the fame founda tions of fenfe and memory as in us, and hath, befides, a fimilar influence on their actions. It is precifely in the fame manner, and with the fame fuccefs, that you might train a dog, or accuftom a child, to expect food on your calling to him in one tone of voice, and to dread your refentment, when you use another. The brutes have evidently the rudiments of this fpecies of rationality, which extends as far in them as the immediate purposes of self-prefervation require, and which, whether you call it reafon or instinct, they both acquire and ufe in the fame manner as we do. That it reaches no farther in them, feems to arife from an original incapacity of claffing, and (if I may use the expreffion) generalifing their perceptions; an exercise which to us very quickly becomes familiar, and is what. chiefly fits us for the use of language. Indeed,

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

BUT that we may be fatisfied, that to this kind of reasoning, in its earliest and fimpleft form, little or no reflection is neceffary, let it be obferved, that it is now univerfally 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 fenfation, fay they, is inftantaneously, followed by a conclufion or judgment founded on experience. The point is determined from the different phafes of the object, found in former trials, to be connected with different diftances, 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 cafe, as I think hath been fufficiently evinced of late, it is manifeft, that this judgment is fo truly inftantaneous, and fo perfectly the refult of feeling and affociation, 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 eafily perfuaded, that he derives

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