Knight said we, not I. The context seems to have been: "That the term 'science fiction' is a misnomer, that trying to get two enthusiasts to agree on a definition of it leads only to bloody knuckles; that better labels have been devised (con't)

(Heinlein's suggestion, 'speculative fiction', is the best, I think), but that we're stuck with this one; and that it will do us no particular harm if we remember that, like 'The Saturday Evening Post', it means what we point to when we say it."