The Source of Immortality
What decides whether a man will become immortal, is not his character but his vitality. Nothing save intensity confers immortality. A man manifests himself more vividly, in proportion as he is strong and unified, effective and unique. Immortality knows nothing of morality or immorality, of good or evil; it measures only work and strength; it demands from a man not purity but unity. Here, morality is nothing; intensity, all.
Stefan Zweig, in 'Casanova: A Study in Self-Portraiture'