The Buddha regarded soul-speculation as useless and illusory. He once said, 'Only through ignorance and delusion do men indulge in the dream that their souls are separate and self-existing entities. Their heart still clings to Self. They are anxious about heaven and they seek the pleasure of Self in heaven. Thus they cannot see the bliss of righteousness and the immortality of truth.' Selfish ideas appear in man's mind due to his conception of Self and craving for existence.