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356 from the second to the first must also, in every case, be equally natural as its passage from the first to the second. But upon farther examination we shall easily discover our mistake. For supposing the second object, beside its reciprocal relation to the first, to have also a strong relation to a third object; in that case the thought, passing from the first object to the second, returns not back with the same facility, tho' the relation continues the same; but is readily carry'd on to the third object, by means of the new relation, which presents itself, and gives a new impulse to the imagination. This new relation, therefore, weakens the tie betwixt the first and second objects. The fancy is by its very nature wavering and inconstant; and considers always two objects as more strongly related together, where it finds the passage equally easy both in going and returning, than where the transition is easy only in one of these motions. The double motion is a kind of a double tie, and binds the objects together in the closest and most intimate manner.

The second marriage of a mother breaks not the relation of child and parent; and that relation suffices to convey my imagination from myself to her with the greatest ease and facility. But after the imagination is arriv'd at this point of view, it finds its object to be surrounded with so many other relations, which challenge its regard, that it knows not which to prefer, and is at a loss what new object to pitch upon. The ties of interest and duty bind her to another family, and prevent that return of the fancy from her to myself, which is necessary to support the union. The thought has no longer the vibration, requisite to set it perfectly at ease, and indulge its inclination to change. It goes with facility, but returns with difficulty; and by that interruption finds the relation much weaken'd from what it wou'd be were the passage open and easy on both sides.

Now to give a reason, why this effect follows not in the same degree upon the second marriage of a father: we may reflect on what has been prov'd already, that tho' the