"SF was born didactic! It originated as a teaching medium-which is why its potential to actually effect some changes in people's attitudes is infinitely greater. It's got representative protagonists, for example-at least it starts like this in the works of H. G. Wells, Jules Verne, and other proto-SF writers. If you look at, say, The War of the Worlds, the human beings there may represent certain attitudes or types, but they are obviously not "individuals" in the sense that characters in the great realistic novels are."