But I have learned from philosophers that among evils one ought not only to choose the least, but also to extract even from these any element of good that they may contain.

[Sed quia sic ab hominibus doctis accepimus, non solum ex malis eligere minima oportere, sed etiam excerpere ex his ipsis, si quid inesset boni ….]

Marcus Tullius Cicero (106-43 BC) Roman orator, statesman, philosopher
De Officiis [On Duties; On Moral Duty; The Offices], Book 3, ch. 1 / sec. 3 (44 BC) [tr. Miller (1913)]
    (Source)

(Source (Latin)). Alternate translation:

This is given us for a rule by the learned, that when several evils are threatening us at once, we should not only choose to undergo the least, but extract some advantage out of them, if it be possible.
[tr. Cockman (1699)]

We have been taught by learned men, not only that we ought to choose the least of evils, but also to extract from them, whatever good they contain.
[tr. McCartney (1798)]

We have bene taught by learned men, that out of evils it is fit not only to choose the least, but also from those very evils to gather whatever good is in them.
[tr. Edmonds (1865)]

Philosophers say that one ought not only of evils to choose the least, but from even these least evils to extract whatever of good there may be in them.
[tr. Peabody (1883)]

Having been taught by philosophers not only to choose the lesser evil but even to extract whatever good is in it.
[tr. Gardiner (1899)]

Learned men have taught us that not only with a choice of evils we should choose the least, but that from the evil we should endeavor to extract some good.
[Harbottle, Dictionary of Quotations (Classical) (1906 ed.)]

Philosophers have taught me not only that one ought to choose the lesser evils but also that even from them one ought to gather whatever good they might contain.
[tr. Edinger (1974)]

See also Thomas à Kempis.