We digest and assimilate all of our thoughts and our mental states, and they become part of our conditioning. There are mental states and impulses that are terribly detrimental, and in meditation we can learn to recognize them as they arise. You could be sitting quite calmly eating your breakfast, when an impulse of hatred, or ill will, or contempt arises. Just like a scuba diver watching a bubble rise, you watch it come up. Then it may pop; or you may go along for the ride and develop it. Then it becomes more like oil on paper, and starts to suffuse your mentality, in which case you have to live with it for a while.
Judgment as an expression of wisdom is not in the business of judging the self. It is in the business of recognizing what are wholesome and unwholesome mental factors.
When ill will arises, wise judgment recognizes it. " Aha! I've heard of you! You are the worst affliction I can suffer from. You completely destroy all loving - kindness. You're the enemy of my happiness, the enemy of my relations with other people. If I go along with you, you'll destroy all my happiness and all my friendships and I'll make myself a thoroughly miserable person. I recognize you" ... That is wisdom and some judgment too. "
Excerpt from The Four Immeasurables - B Alan Wallace