Calumny is like a wasp which harasses you. Raise no hand against it unless you’re sure of killing it, for otherwise it will return to the charge more furious than ever.

Nicolas Chamfort (1741-1794) French writer, epigrammist (b. Nicolas-Sébastien Roch)
Maxims and Thoughts, #302 (1796)
    (Source)

Alt. trans.: "Calumny is like the wasp which worries you, which it were best not to try to get rid of unless you are sure of slaying it; for otherwise it will return to the charge more furious than ever."