The core of The Splendid Feast of Reason is an account of the knowledge that modern science provides. Singer offers an absorbing discussion of how life works; of the nature of reproduction, aging, and death; and of the necessary fragility of the individual life compared with the resilience of life itself. He emphasizes the primary role of the genes in determining the structural organization and the behaviors of living things, including humans. He also stresses the nature and mechanisms of biological evolution, mechanisms that have now been placed in jeopardy because of human ignorance and irrational appetites. Finally, Singer delves into the enigma of the real world, with its irrational and chaotic operations, and offer suggestions of how a rationalist can not only survive but thrive in it.