T 2.2.8.10

Nor will it appear strange, that we may feel a reverst sensation from the happiness and misery of others; since we find the same comparison may give us a kind of malice against ourselves, and make us rejoice for our pains, and grieve for our pleasures. Thus the prospect of past pain is agreeable, when we are satisfy'd with our present condition; as on the other hand our past pleasures give us uneasiness, when we enjoy nothing at present equal to them. The comparison being the same, as when we reflect on the sentiments of others, must be attended with the same effects.