An American science fiction and fantasy writer, he is known for such novels as Okla Hannali, Past Master, and Nine Hundred Grandmothers. His works are notable for their wit, innovative structure, and creative use of language and metaphor.
As a night school student at the University of Tulsa, he studied mathematics and German.
He wrote thirty-two novels and more than two hundred short stories over the course of his career.
He never married. For most of his life, he lived in Tulsa, Oklahoma with his sister Anna.
His literary works have sometimes been compared to those of G. K. Chesterton.