Suppose, that instead of the virtue or vice of a son or brother, which causes first love or hatred, and afterwards pride or humility, we place these good or bad qualities on ourselves, without any immediate connexion with the person, who is related to us: Experience shews us, that by this change of situation the whole chain is broke, and that the mind is not convey’d from one passion to another ….
Always the fundamental importance of pride, the relation of something or someone to the self. Without a relation to self, it losses its influence on the passions.
But if it shou’d happen, that while the relation of ideas, strictly speaking, continues the same, its influence, in causing a transition of the imagination, shou’d no longer take place, ’tis evident its influence on the passions must also cease, as being dependent entirely on that transition.
In other words: I easily imagine myself in love with the person I desire (in love, because there is the double relation so important to Hume). When the passion is no longer there, when I cease to imagine myself in love when in the company of the other person—not by will, but because I see that there is no longer a reason to consider myself in love—it is the end.
When does this natural transition between the idea and the idea (i.e. person) appear and when does it wash away, and why, Hume does not explain.