"Sooner or later for good or ill, a united mankind, equipped with science and power, will probably turn its attention to the other planets, not only for economic exploitation, but also as possible homes for man... The goal for the solar system would seem to be that it should become an interplanetary community of very diverse worlds ... each contributing to the common experience its characteristic view of the universe. Through the pooling of this wealth of experience, through this "commonwealth of worlds," new levels of mental and spiritual development should become possible, levels at present quite inconceivable to man." - Olaf Stapledon, address to the British Interplanetary Society, 1948