One of the most profound constants of Naturalism is to denounce everything that is sadness, everything that is the cause of sadness, and everything that needs sadness to exercise its power. From Lucretius to Nietzsche, the same end is pursued and attained. Naturalism makes of thought and sensibility an affirmation. It directs its attack against the prestige of the negative: it deprives the negative of all its power; it refuses to the spirit of the negative the right to speak in the name of philosophy. … Lucretius established for a long time to come the implications of naturalism: the positivity of Nature; Naturalism as the philosophy of affirmation; pluralism linked with multiple affirmation; sensualism connected with the joy of the diverse; and the practical critique of all mystifications.
– Gilles Deleuze, The Logic of Sense (279)