In the third place, love and hatred have often a slow growth. The good qualities or kind offices of a person, raise in me pleasant emotions; which, by reiterated views, are swelled into a passion involving desire of that person’s happiness. This desire being often put in exercise, works gradually a change internally; and at last produceth in me a settled habit of affection for that person, now my friend. Affection thus produced, operates precisely like an original propensity. To enliven it into a passion, no more is required but the real or ideal presence of the object. The habit of aversion or hatred is brought on in the same manner. And here I must observe by the way, that love and hatred signify commonly affection, not passion. The bulk indeed of our passions, are these affections inflamed into a passion by different circumstances. The affection of love I bear to my son, is inflamed into the passion of fear, when he is in danger; becomes hope, when he hath a prospect of good fortune; becomes admiration, when he performs a laudable action; and shame, when he commits any wrong. Aversion, again, becomes fear when there is a prospect of good fortune to my enemy; becomes hope when he is in danger; becomes joy when he is in distress; and sorrow when a laudable action is performed by him. Fourthly, the growth of some passions depends often on occasional circumstances. Obstacles to gratification never fail to augment and inflame a passion. A constant endeavour to remove the obstacle, preserves the object of the passion ever in view, which swells the passion by impressions frequently reiterated. Thus the restraint of conscience, when an obstacle to love, agitates the mind and inflames the passion: Quod licet, ingratum est: quod non licet, acrius urit. Si nunquam Danaën habuisset ahenea turris, Non esset Danaë de Jove facta parens. _Ovid. Amor. l. 2._ At the same time, the mind distressed with the obstacle, is disposed to indulge its distress by magnifying the pleasure of gratification; which naturally inflames desire. Shakespear expresses this observation finely: All impediments in fancy’s course, Are motives of more fancy. We need no better example than a lover who hath many rivals. Even the caprices of a mistress have the effect to inflame love. These occasioning uncertainty of success, tend naturally to make the anxious lover overvalue the happiness of fruition.