T 2.1.9.4

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 convey'd 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. 'Tis 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 possess'd, and which it cou'd recal upon occasion. From this reasoning, as well as from undoubted experience, we may conclude, that an association of ideas, however necessary, is not alone sufficient to give rise to any passion.