Dumas Debate

I just love the works of Alexandre Dumas; I read (or rather re-read) one every summer. This summer it's The Count of Monte Cristo. One of the things I love about Dumas is that he captures human nature so well, and manages to get his characters to discuss all kinds of things without them being aware of it. In today's reading I've found a discussion that I'd like to extend to my readers.

In this excerpt, Dantes has just been falsely accused of treason and Villefort is questioning him.

Villefort: "But you may have excited jealousy. You are about to become captain at nineteen—an elevated post; you are about to marry a pretty girl, who loves you; and these two pieces of good fortune may have excited the envy of some one."

Dantes: "You are right; you know men better than I do, and what you say may possibly be the case, I confess; but if such persons are among my acquaintances I prefer not to know it, because then I should be forced to hate them."

Villefort: "You are wrong; you should always strive to see clearly around you."

Who's right: Dantes or Villefort? Is it better to know who your secret enemies are, or is that knowledge destructive? Discuss.