Demades, the Athenian, condemned a man of the city, whose trade was to sell such necessaries as belonged to burials, under the pretense that he asked too much profit for them, and that such profit could not accrue to him, without the death of many people. This judgment seems to be ill grounded, because no man profits but by the loss of others; and, by the same rule, he should condemn all manner of gain. The merchant thrives not but by the debauchery of youth, the husbandman only by dearth of grain, the architect but by the ruin of buildings, lawyers by the suits and contentions of men: Honour itself and the practice of religious Ministers are drawn from our death and vices. No physician delights in the health of his own friends, says the ancient Greek comic writer, nor no soldier is pleased with the peace of his city, and so of the rest. And, which is worse, let every man sound his own conscience, and he will find that his private wishes spring and his secret hopes grow at the pain and loss of others. When I considered this, I began to think how Nature as a whole does not contradict its general policy; for physicians hold, that The birth, nourishment, and increase of every thing is the alteration and corruption of another.

Whatever from its bounds does pass changed,

that strait is the death of that which it formerly was.

 —Lucretius, ii. 752.

– Michel de Montaigne, “The Profit of One Man is the Damage of Another” Chapter XXI of Book 1 of Volume of Essays. [You can find a different translation by Charles Cotton (1877) at Project Gutenberg).]