T 2.2.11.5

This account of love is not peculiar to my system, but is unavoidable on any hypothesis. The three affections, which compose this passion, are evidently distinct, and has each of |them its distinct object. 'Tis certain, therefore, that 'tis only by their relation they produce each other. But the relation of passions is not alone sufficient. 'Tis likewise necessary, there shou'd be a relation of ideas. The beauty of one person never inspires us with love for another. This then is a sensible proof of the double relation of impressions and ideas. From one instance so evident as this we may form a judgment of the rest.