A nicely edited collection of sci-fi novellas from the 1940s and 1950s by Poul Anderson, Henry Kuttner, Eric Frank Russell, and Theodore Sturgeon, each introduced by editor Groff Conklin (who might have the coolest name ever conceived). Each story focuses on the uniqueness of the human race, and the humanness of humanity that stays true even in the distant future. I particularly liked Theodore Sturgeon's "The Claustrophile" and Henry Kuttner's "The Children's Hour."