 But if truthfulness is a core value for Nietzsche, he is nevertheless famous for insisting that we also need illusion to live well. From the beginning of his career to the end, he insisted on the irreplaceable value of art precisely because of its power to ensconce us in illusion. The idea was a major theme of The Birth of Tragedy (BT 1, 3, 4, 7, 15, 25), and although Nietzsche later came to see the point somewhat differently, he never gave it up (see GS 107, also TI IX, 7–9). In a slogan, “We possess art lest we perish of the truth” (KSA 16[40] 13: 500).