Know the Lie and the Truth

To know the truth one must recognize the lie. Read The New York Times, More Lying.

With acknowledgment to Sun Tzu (on knowing the enemy):

If you know the lie and know the truth, you need not fear the argument.
If you know truth but not the lie, for every victory gained you will also suffer a defeat.
If you know neither the lie nor the truth, you will succumb in every battle.