How selfish soever man may be supposed, there are evidently some principles in his nature, which interest him in the fortune of others, and render their happiness necessary to him, though he derives nothing from it except the pleasure of seeing it. Of this kind is pity or compassion, the emotion which we feel for the misery of others, when we either see it, or are made to conceive it in a very lively manner. That we often derive sorrow from the sorrow of others, is a matter of fact too obvious to require any instances to prove it; for this sentiment, like all the other original passions of human nature, is by no means confined to the virtuous and humane, though they perhaps may feel it with the most exquisite sensibility. The greatest ruffian, the most hardened violator of the laws of society, is not altogether without it.
As we have no immediate experience of what other men feel, we can form no idea of the manner in which they are affected, but by conceiving what we ourselves should feel in the like situation. Though our brother is upon the rack, as long as we ourselves are at our ease, our senses will never inform us of what he suffers. They never did, and never can, carry us beyond our own person, and it is by the imagination only that we can form any conception of what are his sensations. Neither can that faculty help us to this any other way, than by representing to us what would be our own, if we were in his case. It is the impressions of our own senses only, not those of his, which our imaginations copy. By the imagination we place ourselves in his situation, we conceive ourselves enduring all the same torments, we enter as it were into his body, and become in some measure the same person with him, and thence form some idea of his sensations, and even feel something which, though weaker in degree, is not altogether unlike them. His agonies, when they are thus brought home to ourselves, when we have thus adopted and made them our own, begin at last to affect us, and we then tremble and shudder at the thought of what he feels. For as to be in pain or distress of any kind excites the most excessive sorrow, so to conceive or to imagine that we are in it, excites some degree of the same emotion, in proportion to the vivacity or dulness of the conception.
That this is the source of our fellow-feeling for the misery of others, that it is by changing places in fancy with the sufferer, that we come either to conceive or to be affected by what he feels, may be demonstrated by many obvious observations, if it should not be thought sufficiently evident of itself. When we see a stroke aimed and just ready to fall upon the leg or arm of another person, we naturally shrink and draw back our own leg or our own arm; and when it does fall, we feel it in some measure, and are hurt by it as well as the sufferer. The mob, when they are gazing at a dancer on the slack rope, naturally writhe and twist and balance their own bodies, as they see him do, and as they feel that they themselves must do if in his situation. Persons of delicate fibres and a weak constitution of body complain, that in looking on the sores and ulcers which are exposed by beggars in the streets, they are apt to feel an itching or uneasy sensation in the correspondent part of their own bodies. The horror which they conceive at the misery of those wretches affects that particular part in themselves more than any other; because that horror arises from conceiving what they themselves would suffer, if they really were the wretches whom they are looking upon, and if that particular part in themselves was actually affected in the same miserable manner. The very force of this conception is sufficient, in their feeble frames, to produce that itching or uneasy sensation complained of. Men of the most robust make, observe that in looking upon sore eyes they often feel a very sensible soreness in their own, which proceeds from the same reason; that organ being in the strongest man more delicate, than any other part of the body is in the weakest.
Neither is it those circumstances only, which create pain or sorrow, that call forth our fellow-feeling. Whatever is the passion which arises from any object in the person principally concerned, an analogous emotion springs up, at the thought of his situation, in the breast of every attentive spectator. Our joy for the deliverance of those heroes of tragedy or romance who interest us, is as sincere as our grief for their distress, and our fellow-feeling with their misery is not more real than that with their happiness. We enter into their gratitude towards those faithful friends who did not desert them in their difficulties; and we heartily go along with their resentment against those perfidious traitors who injured, abandoned, or deceived them. In every passion of which the mind of man is susceptible, the emotions of the by-stander always correspond to hat, by bringing the case home to himself, he imagines should be the sentiments of the sufferer.
Pity and compassion are words appropriated to signify our fellow-feeling with the sorrow of others. Sympathy, though its meaning was, perhaps, originally the same, may now, however, without much impropriety, be made use of to denote our fellow-feeling with any passion whatever.