" Modern” science fiction, generally dated as having begun in late 1937 with the ascent of Campbell, was a literature centered around a compact group of people. It was no Bloombury but there could have been no more than fifty core figures who did 90% of the writing and editing. All of them knew one another, most knew one well, lived together, married one another, collaborated, bought each other’s material, and so on. For a field which was conceptually based on expansion, the smashing of barriers, the far-reaching and so on, science fiction was amazingly insular. "

― Barry N. Malzberg , Breakfast in the Ruins: Science Fiction in the Last Millennium