Most fortunately, all this reasoning is found to be exactly conformable to experience and the phenomena of the passions. Suppose I were travelling with a companion through a country to which we are both utter strangers; 'tis evident, that if the prospects be beautiful, the roads agreeable, and the inns commodious, this may put me into good humour both with myself and fellow-traveller. But as we suppose that this country has no relation either to myself or friend, it can never be the immediate cause of pride or love; and, therefore, if I found not the passion on some other object that bears either of us a closer relation, my emotions are rather to be considered as the overflowings of an elevate or humane disposition, than as an established passion. The case is the same where the object produces uneasiness. _Fourth experiment_. Having found, that neither an object, without any relation of ideas or impressions, nor an object that has only one relation, can ever cause pride or humility, love or hatred; reason alone may convince us, without any farther experiment, that whatever has a double relation must necessarily excite these passions; since 'tis evident they must have some cause. But, to leave as little room for doubt as possible, let us renew our experiments, and see whether the event in this case answers our expectation. I chuse an object, such as virtue, that causes a separate satisfaction: on this object I bestow a relation to self; and find, that from this disposition of affairs there immediately arises a passion. But what passion? That very one of pride, to which this object bears a double relation. Its idea is related to that of self, the object of the passion: the sensation it causes resembles the sensation of the passion. That I may be sure I am not mistaken in this experiment, I remove first one relation, then another, and find that each removal destroys the passion, and leaves the object perfectly indifferent. But I am not content with this. I make a still farther trial; and instead of removing the relation, I only change it for one of a different kind. I suppose the virtue to belong to my companion, not to myself; and observe what follows from this alteration. I immediately perceive the affections to wheel about, and leaving pride, where there is only one relation, viz. of impressions, fall to the side of love, where they are attracted by a double relation of impressions and ideas. By repeating the same experiment in changing anew the relation of ideas, I bring the affections back to pride; and, by a new repetition, I again place them at love or kindness. Being fully convinced of the influence of this relation, I try the effects of the other; and, by changing virtue for vice, convert the pleasant impression which arises from the former, into the disagreeable one which proceeds from the latter. The effect still answers expectation. Vice, when placed on another, excites,