Well then, for a man to take something from his neighbour and to profit by his neighbour's loss is more contrary to Nature than is death or poverty or pain or anything else that can affect either our person or our property.
 Marcus Tullius Cicero, On Duties (44 BC). copy citation

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Author Marcus Tullius Cicero
Source On Duties
Topic poverty loss
Date 44 BC
Language English
Reference
Note Translated by Walter Miller
Weblink http://www.constitution.org/rom/de_officiis.htm

Context

“It is their teachings that I am following in these books, and for these problems, if conducted by those who consider whatever is morally right also expedient and nothing expedient that is not at the same time morally right, will be more illuminating than if conducted by those who think that something not expedient may be morally right and that something not morally right may be expedient. But our New Academy allows us wide liberty, so that it is within my right to defend any theory that presents itself to me as most probable. But to return to my rule. {21} V. Well then, for a man to take something from his neighbour and to profit by his neighbour's loss is more contrary to Nature than is death or poverty or pain or anything else that can affect either our person or our property. For, in the first place, injustice is fatal to social life and fellowship between man and man. For, if we are so disposed that each, to gain some personal profit, will defraud or injure his neighbour, then those bonds of human society, which are most in accord with Nature's laws, must of {22} necessity be broken.” source