He must teach himself that the basest of all things is to be afraid: and, teaching himself that, forget it forever, leaving no room in his workshop for anything but hte old verities and truths of the heart, the old universal truths lacking which any story is ephemeral and doomes-love and honor and pity and pride and compassion and sacrifice. -William faulkner
Faulkner's speech was given at a time when the threat of nuclear invasion was very strong and there was a fear of what might happen.
He is saying that it is important to learn not to be frightened, to recognize that fear is in itself a dangerous and valueless emotion, and that it is important to remember the ancient and basic values of love, honour, compassion and understanding. Without these values, people are concerned only with self-centred matters.