It is obvious, that people associate together according to their particular tempers and dispositions, and that men of gay tempers naturally love the gay; as the serious bear an affection to the serious.  This not only happens, where they remark this resemblance betwixt themselves and others, but also by the natural course of the disposition, and by a certain sympathy, which always arises betwixt similar characters.  Where they remark the resemblance, it operates after the manner of a relation, by producing a connexion of ideas.  Where they do not remark it, it operates by some other principle; and if this latter principle be similar to the former, it must be received as a confirmation of the foregoing reasoning.

The idea of ourselves is always intimately present to us, and conveys a sensible degree of vivacity to the idea of any other object, to which we are related.  This lively idea changes by degrees into a real impression; these two kinds of perception being in a great measure the same, and differing only in their degrees of force and vivacity.  But this change must be produced with the greater ease, that our natural temper gives us a propensity to the same impression, which we observe in others, and makes it arise upon any slight occasion.  In that case resemblance converts the idea into an impression, not only by means of the relation, and by transfusing the original vivacity into the related idea; but also by presenting such materials as take fire from the least spark.  And as in both cases a love or affection arises from the resemblance, we may learn that a sympathy with others is agreeable only by giving an emotion to the spirits, since an easy sympathy and correspondent emotions are alone common to relation, acquaintance, and resemblance.

The great propensity men have to pride may be considered as another similar phaenomenon.  It often happens, that after we have lived a considerable time in any city; however at first it might be disagreeable to us; yet as we become familiar with the objects, and contact an acquaintance, though merely with the streets and buildings, the aversion diminishes by degrees, and at last changes into the opposite passion.  The mind finds a satisfaction and ease in the view of objects, to which it is accustomed, and naturally prefers them to others, which, though, perhaps, in themselves more valuable, are less known to it.  By the same quality of the mind we are seduced into a good opinion of ourselves, and of all objects, that belong to us.  They appear in a stronger light; are more agreeable; and consequently fitter subjects of pride and vanity, than any other.