No quality of human nature is more remarkable, both in itself and in its consequences, than that propensity we have to sympathize with others, and to receive by communication their inclinations and sentiments, however different from, or even contrary to, our own. This is not only conspicuous in children, who implicitly embrace every opinion proposed to them; but also in men of the greatest judgment and understanding, who find it very difficult to follow their own reason or inclination, in opposition to that of their friends and daily companions. To this principle we ought to ascribe the great uniformity we may observe in the humours and turn of thinking of those of the same nation; and 'tis much more probable, that this resemblance arises from sympathy, than from any influence of the soil and climate, which, though they continue invariably the same, are not able to preserve the character of a nation the same for a century together. A good-natured man finds himself in an instant of the same humour with his company; and even the proudest and most surly take a tincture from their countrymen and acquaintance. A cheerful countenance infuses a sensible complacency and serenity into my mind; as an angry or sorrowful one throws a sudden damp upon me. Hatred, resentment, esteem, love, courage, mirth and melancholy; all these passions I feel more from communication, than from my own natural temper and disposition. So remarkable a phenomenon merits our attention, and must be traced up to its first principles. When any affection is infused by sympathy, it is at first known only by its effects, and by those external signs in the countenance and conversation, which convey an idea of it. This idea is presently converted into an impression, and acquires such a degree of force and vivacity, as to become the very passion itself, and produce an equal emotion as any original affection. However instantaneous this change of the idea into an impression may be, it proceeds from certain views and reflections, which will not escape the strict scrutiny of a philosopher, though they may the person himself who makes them. 'Tis evident that the idea, or rather impression of ourselves, is always intimately present with us, and that our consciousness gives us so lively a conception of our own person, that 'tis not possible to imagine that any thing can in this particular go beyond it. Whatever object, therefore, is related to ourselves, must be conceived with a like vivacity of conception, according to the foregoing principles; and though this relation should not be so strong as that of causation, it must still have a considerable influence. Resemblance and contiguity are relations not to be neglected; especially when, by an inference from cause and effect, and by the observation of external signs, we are informed of the real existence of the object, which is resembling or contiguous.