Introduction / Groff Conklin -- Microcosmic god / Theodore Sturgeon -- Commencement night / Richard Ashby -- Deep range / Arthur C. Clarke -- Machine made / J.T. McIntosh -- Trip one / Edward Grendon -- Venus is a man's world / William Tenn -- Good-bye, Ilha! / Lawrence Manning -- Misbegotten missionary / Isaac Asimov -- Ethical equations / Murray Leinster -- Misfit / Robert A. Heinlein -- Genius / Poul Anderson -- Basic right / Eric Frank Russell.