“Fear of evil is greater than the evil itself.”

8
Variant translation: No pleasure is itself a bad thing, but the things that produce some kinds of pleasure, bring along with them unpleasantness that is much greater than the pleasure itself.
Sovereign Maxims

ἐν παντὶ πράγει δ᾽ ἔσθ᾽ ὁμιλίας κακῆς
κάκιον οὐδέν
Source: Seven Against Thebes (467 BC), lines 599–600 (tr. David Grene)

Source: Life, Sex, and Ideas: The Good Life Without God (2002), Chapter 9, “Evil” (p. 34)

The Law (1850)

Plato, Phaedo

Il faut de plus grandes vertus pour soutenir la bonne fortune que la mauvaise.
Maxim 25.
Reflections; or Sentences and Moral Maxims (1665–1678)

Letter to his wife, Mary Anne Lee http://www.fair-use.org/robert-e-lee/letter-to-his-wife-on-slavery (27 December 1856)
1850s
Context: In this enlightened age, there are few I believe, but what will acknowledge, that slavery as an institution, is a moral & political evil in any Country. It is useless to expatiate on its disadvantages. I think it however a greater evil to the white man than to the black race, & while my feelings are strongly enlisted in behalf of the latter, my sympathies are more strong for the former. The blacks are immeasurably better off here than in Africa, morally, socially & physically. The painful discipline they are undergoing, is necessary for their instruction as a race, & I hope will prepare & lead them to better things. How long their subjugation may be necessary is known & ordered by a wise Merciful Providence.

Source: The Invention of Wings

"The Mystery of the Five Hundred Diamonds," from The Triumphs of Euguene Valmont (1906)