Mankind are by nature so closely united, there is such a correspondence between the inward sensations of one man and those of another, that disgrace is as much avoided as bodily pain, and to be the object of esteem and love as much desired as any external goods; and in many particular cases persons are carried on to do good to others, as the end their affection tends to and rests in; and manifest that they find real satisfaction and enjoyment in this course of behaviour. There is such a natural principle of attraction in man towards man that having trod the same tract of land, having breathed in the same climate, barely having been born in the same artificial district or division, becomes the occasion of contracting acquaintances and familiarities many years after; for anything may serve the purpose. Thus relations merely nominal are sought and invented, not by governors, but by the lowest of the people, which are found sufficient to hold mankind together in little fraternities and copartnerships: weak ties indeed, and what may afford fund enough for ridicule, if they are absurdly considered as the real principles of that union: but they are in truth merely the occasions, as anything may be of anything, upon which our nature carries us on according to its own previous bent and bias; which occasions therefore would be nothing at all were there not this prior disposition and bias of nature. Men are so much one body that in a peculiar manner they feel for each other shame, sudden danger, resentment, honour, prosperity, distress; one or another, or all of these, from the social nature in general, from benevolence, upon the occasion of natural relation, acquaintance, protection, dependence; each of these being distinct cements of society. And therefore to have no restraint from, no regard to, others in our behaviour, is the speculative absurdity of considering ourselves as single and independent, as having nothing in our nature which has respect to our fellow-creatures, reduced to action and practice. And this is the same absurdity as to suppose a hand, or any part, to have no natural respect to any other, or to the whole body.
(From the sermon Upon Human Nature, Sermon 1 of the Fifteen Sermons)