These trifles are connected with the resembling qualities in us; and these qualities in us, being parts, are connected with the whole; and by that means form a chain of several links of the person we resemble.

But besides that this multitude of relations must weaken the connexion; it is evident the mind, in passing from the shining qualities to the trivial ones, must by that contrast the better perceive the minuteness of the latter, and be in some measure ashamed of the comparison and resemblance.
The relation, therefore, of contiguity, or that of causation, betwixt the cause and object of pride and humility, is alone requisite to give rise to these passions; and these relations are nothing else but qualities, by which the imagination is conveyed from one idea to another.

Now let us consider what effect these can possibly have upon the mind, and by what means they become so requisite to the production of the passions.

It is evident, that the association of ideas operates in so silent and imperceptible a manner, that we are scarce sensible of it, and discover it more by its effects than by any immediate feeling or perception.

It produces no emotion, and gives rise to no new impression of any kind, but only modifies those ideas, of which the mind was formerly possessed, and which it coued recal upon occasion.