That Douglass and King could approvingly quote Jefferson, himself a hypocritical and in some ways dishonorable man, does not compromise the rationality of their arguments but reinforces it. We should care about people’s virtue when considering them as friends, but not when considering the ideas they voice. Ideas are true or false, consistent or contradictory, conducive to human welfare or not, regardless of who thinks them.

— Steven Pinker, Rationality