Polymath is a science fiction novel by John Brunner, first published in 1974 by DAW Books, an expansion of Castaways' World (Ace 1963).
A spacecraft filled with refugees from a cosmic catastrophe crash-lands on an unmapped planet. There the survivors must face the reality of their precarious situation; the ship was lost and little had been salvaged from it. Everything comes to depend on one bright young man accidentally among them, a trainee planet-builder, or "polymath". While it would have been his job to oversee all aspects of establishing a successful colony he faces major difficulties; not only is his education incomplete, he had been studying a vastly different planet.