Philosophers countenancing optimism, understood as the view that the world is absolutely valuable, often conclude that human existence, too, must be highly valuable. Philosophers upholding pessimism, viewing the world as valueless, often deem human life futile. Both positions have been vigorously defended and harshly criticized. Standardly, a philosopher regarding optimism as naïve offers an anti-optimistic view, which is in turn accused by others of latent optimism, illegitimately overvaluing the world and oneself, for instance by positing some desirable and achievable state for the world and oneself to be in, or by reaffirming the world as is. Optimism, however, need not imply that human existence is significantly valuable. Instead, optimists sometimes establish an axiological hierarchy between the various parts of the world, with human beings at or near the bottom. My book project traces and analyzes the long history of this debate, focusing on Aristotle, Maimonides, Spinoza, Schopenhauer, Nietzsche and Camus.