"Science fiction, thus considered, is not a mere pocket in the varicolored vest of modern writing; it is a new kind of fiction, the beginnings of a long-delayed revolution in letters consequent upon the revolutions that the last two hundred years have witnessed in science, industry, and politics. By this I do not at all mean that it is the only possible literature of the present time, just that it is the type most peculiar to it, most indicative of its larger intellectual trends."
January 1, 1970
https://en.wikiquote.org/wiki/Science_fiction