We need not lose time in describing the co-operation of the foregoing principle with surprise in producing the effect that is felt upon the appearance of any unusual resemblance or contrast. Surprise first operates, and carries our opinion of the resemblance or contrast beyond the truth. The principle we have been describing carries us still farther; for being bent upon gratification, it forces upon the mind a conviction that the resemblance or contrast is complete. We need no better illustration than the resemblance that is fancied in some pebbles to a tree or an insect. The resemblance, however faint in reality, is conceived to be wonderfully perfect. This tendency to complete a resemblance acting jointly with surprise, carries the mind sometimes so far as even to presume upon future events. In the Greek tragedy, intitled, _Phineides_, those unhappy women, seeing the place where it was intended they should be slain, cried out with anguish, “They now saw their cruel destiny had condemned them to die in that place, being the same where they had been exposed in their infancy[83].” This remarkable principle which inclines us to advance every thing to its perfection, not only co-operates with surprise to deceive the mind, but of itself is able to produce that effect. Of this we see many instances where there is no place for surprise. The first instance I shall give is of resemblance. _Unumquodque eodem modo dissolvitur quo colligatum est_, is a maxim in the Roman law that has no foundation in truth. For tying and loosing, building and demolishing, are acts opposite to each other, and are performed by opposite means. But when these acts are connected by their relation to the same subject, their connection leads us to imagine a sort of resemblance betwixt them, which the foregoing principle makes us conceive to be as complete as possible. The next instance shall be of contrast. Addison observes[84], “That the palest features look the most agreeable in white; that a face which is overflushed appears to advantage in the deepest scarlet; and that a dark complexion is not a little alleviated by a black hood.” The foregoing principle serves to account for these appearances. To make this evident, one of the cases shall suffice. A complexion, however dark, never approaches to black. When these colours appear together, their opposition strikes us; and the propensity we have to complete the opposition, makes the darkness of complexion vanish out of sight.