This resemblance is the cause of the confusion and mistake, and makes us substitute the notion of identity, instead of that of related objects.

However at one instant we may consider the related succession as variable or interrupted, we are sure the next to ascribe to it a perfect identity, and regard it as enviable and uninterrupted.

Our propensity to this mistake is so great from the resemblance above-mentioned, that we fall into it before we are aware; and though we incessantly correct ourselves by reflection, and return to a more accurate method of thinking, yet we cannot long sustain our philosophy, or take off this biass from the imagination.

Our last resource is to yield to it, and boldly assert that these different related objects are in effect the same, however interrupted and variable.

In order to justify to ourselves this absurdity, we often feign some new and unintelligible principle, that connects the objects together, and prevents their interruption or variation.