If nobody were to know or even to suspect the truth, when you do anything to gain riches or power or sovereignty or sensual gratification — if your act should be hidden for ever from the knowledge of gods and men, would you do it? […] Should they answer that, if impunity were assured, they would do what was most to their selfish interest, that would be a confession that they are criminally minded; should they say that they would not do so, they would be granting that all things in and of themselves immoral should be avoided.

[Si nemo sciturus, nemo ne suspicaturus quidemn sit, curn aliquid divitiarum, potentiae, dominationis, libidinis causa feceris, si id dis hominibusque futurum sit semper ignotuml, sisne facturus. […] Si responderint se impunitate proposita facturos, quod expediat, facinorosos se esse fateantur, si negent, omnia turpia per se ipsa fugienda esse concedant.]

Marcus Tullius Cicero (106-43 BC) Roman orator, statesman, philosopher
De Officiis [On Duties; On Moral Duty; The Offices], Book 3, ch. 9 / sec. 39 (44 BC) [tr. Miller (1913)]
    (Source)

Original Latin. Alternate translations:

• "Suppose you could do any dishonest action, for the gratifying of a lustful, covetous, or ambitious desire, so as that no one living could either know or suspect it, but both gods and men must be kept perfectly in ignorance; whether in such case would you do it or no? [...] If they say they would gratify such desires on assurance of impunity, we may know them to be villains by their own confession; but if they deny it, they may be forced to grant that every base and dishonest action is barely as such to be shunned and detested." [tr. Cockman (1699)]


• "If no man should know, or not even suspect, that you were any way engaged in the pursuit of wealth, power, or domination, or for the gratification of lust; and if it were to be forever unknown to gods and men; would you behave so? [...] If they answer, upon impunity being proposed, they would do what is profitable, they may confess themselves profligate, but if they refuse that they would follow such a course, they admit that every vice from its own nature ought to be avoided." [tr. McCartney (1798)]


• "If nobody were to know, nobody even to suspect that you were doing anything for the sake of riches, power, domination, lust -- if it would be for ever unknown to gods and men, would you do it? [...] If they answer that they would do, if impunity were offered, what it was their interest to do, they must confess that they are wicked; if they deny that they would do so, they must admit that all base actions are to be shunned on their own account." [tr. Edmonds (1865)]


• "If no one would ever know, if no one would ever suspect, when you performed some act for the sake of wealth, power, ascendency, lust, -- if it would remain forever unknown to gods and men, would you do it? [...] If they answer that they would do what seemed expedient if assured of impunity, they may confess themselves atrociously guilty; and if they make the contrary answer, that they may grant that whatever is wrong in itself ought to be shunned." [tr. Peabody (1883)]