Anyone who has travelled this wide earth knows that there are greedy men who are like ferocious tigers, and smooth-tongued women who are as dangerous as devouring serpents. The evil of such people lies not so much in the character which they reveal as in the character which they hide. It is the suave dissembler who reproduces the words of goodness without its heart and who cynically divorces creed from conduct that we must fear, rather than the man who has "scoundrel" stamped all over his face and actions. We are not apt to be on our guard against a silky voice, saintly manner, and smiling lips, but when these things hide a devil's heart of dark intentions, we are in peril of being undone.
-- Notebooks Category 11: The Negatives > Chapter 3: Their Presence in The World > # 10