I must say a word about fear. It is life's only true opponent. Only fear can defeat life. It is a clever, treacherous adversary, how well I know. It has no decency, respects no law or convention, shows no mercy. It goes for your weakest spot, which it finds with unerring ease. It begins in your mind, always. (2.56.1)

The matter is difficult to put into words. For fear, real fear, such as shakes you to your foundation, such as you feel when you are brought face to face with your mortal end, nestles in your memory like a gangrene; it seeks to rot everything, even the words with which to speak of it. [...]. You must fight hard to shine the light of words upon it. Because if you don't, if your fear becomes a wordless darkness that you avoid, perhaps even manage to forget, you open yourself to further attacks of fear because you never truly fought the opponent who defeated you. (2.56.4)