The Extra Man by E.C. Tubb

There were two. Rosslyn, the pilot, and Comain, the dreamer. Rosslyn died in space, frozen, preserved for two centuries until found and resurrected by a miracle of future surgery. Comain…? Comain remained on Earth, and crystallised his dreams, and when Rosslyn returned he found a civilisation beyond his wildest imaginings. Women ruled the planet, guided solely by the automatic and relentless predictions of a tremendous and frightening machine. A machine that foretold the future and determined the actions of an entire world.

Into this assured and new civilisation Rosslyn came, and the impact of his presence brought near chaos. He had to be assimilated—or eliminated.

Rosslyn wanted neither. He became the pawn in a colossal gamble, with power as the prize . . . and the future of Mankind at stake!