Charles Sumner was a man of vision. The senator from
Massachusetts knew that slavery was wrong. He devoted his fiery
oratory to denouncing the profound evil it represented, but
Charles Sumner lacked a virtue I would call suppleness. What is
that? It’s a combination of the classical virtues. It’s the
prudence to bend a bit, because you truly are confident about
“which way is up." It’s the justice to hear whatever measure of
truth there is in your opponent’s viewpoint, realizing that you
possess no patent on truth. It’s the temperance of attending the
advent of the right, lest, in your haste, you destroy other
goods. And finally, it’s the courage to grow and to adjust, to
be spry in responding to life.  Charles Sumner lacked the
suppleness to distinguish between the evil that people do and
the inherent goodness of people themselves.   As Amanda Foreman
notes in her new history of Britain’s role in America’s Civil
War, A World on Fire, Sumner  was incapable of trimming his
actions or modulating his speeches to s