to depend on the actual juxta-position of two, or more local impressions, which being thus accidentally brought together have thrown a sort of grappling irons over one another, and continue to act in concert in consequence of this immediate local communication. It is clear that in this case none but the individual, or numerical impressions so united can have any power over each other. No matter how like any other impression may be to any of the associated ones: if it does not agree in place as well as kind, it might as well not exist at all; its influence can no more be felt in the seat of the first, than if it were parcel of another intellect, or floated into the most distant parts of space. Again: suppose association to consist not in connecting different local impressions, but in reconciling different heterogeneous actions of the same thinking principle, "in subduing the one even to the very quality of the other"; here the disposition of the mind being the chief thing concerned, not only those very identical impressions will coalesce together which have been previously associated, but any other very similar impressions to these will have a facility in exciting one another, that is in acting upon the mind at the same time, their association depending solely on the habitual disposition of the mind to receive such and such impressions when pre-occupied by certain others, their local relation to each other being the same in all cases.—The moment it is admitted not to be necessary to association that the very individual impressions should be actually revived, the foundation of all the inferences which have been built on this principle is completely done away.
Association then is only one of the ways in which ideas are recollected or brought back into the mind. Another view of the subject remains, which is to consider their effects after they get there as well as how they are introduced:
