One of the biggest roles of science fiction is to prepare people to accept the future without pain and to encourage a flexibility of mind. Politicians should read science fiction, not westerns and detective stories. Two-thirds of 2001 is realistic — hardware and technology — to establish background for the metaphysical, philosophical, and religious meanings later.

As quoted in The Making of Kubrick's 2001 (1970) by Jerome Agel, p. 300