It is, perhaps, one of the most pernicious errors of a rash and inconsiderate life, the common ignorance of the world in the matter of exchanging benefits . And this arises from a mistake, partly in the person that we would oblige, and partly in the thing itself. To begin with the latter: “A benefit is a good office, done with intention and judgment;” that is to say, with a due regard to all the circumstances of what , how , why , when , where , to whom , how much , and the like; or otherwise: “It is a voluntary and benevolent action that delights the giver in the comfort it brings to the receiver.” It will be hard to draw this subject, either into method or compass: the one, because of the infinite variety and complication of cases; the other, by reason of the large extent of it: for the whole business (almost) of mankind in society falls under this head; the duties of kings and subjects, husbands and wives, parents and children, masters and servants, natives and strangers, high and low, rich and poor, strong and weak, friends and enemies.