When plunder has become a way of life for a group of men living together in society, they create for themselves in the course of time a legal system that authorizes it and a moral code that glorifies it.

[Lorsque la Spoliation est devenue le moyen d’existence d’une agglomération d’hommes unis entre eux par le lien social, ils se font bientôt une loi qui la sanctionne, une morale qui la glorifie.]

Frédéric Bastiat (1801-1850) French philosopher, economist, politician

Economic Sophisms [Sophismes Économiques], 2nd Series, ch. 1 “Physiology of Plunder [Physiologie de la Spoliation]” (1848) [tr. Goddard (1964)]
    (Source)

(Source (French)). Other translations:

When Spoliation has once become the recognised means of existence of a body of men united and held together by social ties, they soon proceed to frame a law which sanctions it, and to adopt a system of morals which sanctifies it.
[tr. Stirling (1873)]

When Plunder becomes a way of life for a group of men in a society, over the course of time they create for themselves a legal system that authorizes it and a moral code that glorifies it.
[tr. Goddard (variant/paraphrase)]