There are, without doubt, great possibilities in the serious exploitation of the astronomical tale; as a few semi-classics like "The War of the Worlds", "The Last and First Men", "Station X", "The Red Brain", and Clark Ashton Smith's best work prove. But the pioneers must be prepared to labour without financial return, professional recognition, or the encouragement of a reading majority whose taste has been seriously warped by the rubbish it has devoured. Fortunately sincere artistic creation is its own incentive and reward, so that despite all obstacles we need not despair of the future of a fresh literary form whose present lack of development leaves all the more room for brilliant and fruitful experimentation.

"Some Notes on Interplanetary Fiction", Californian 3, No. 3 (Winter 1935): 39-42. Published in Collected Essays, Volume 2: Literary Criticism edited by S. T. Joshi, p. 178