Continuum

In the purest kind of science fiction, the characters are in service to the story, and the story, whether it's about exploring alien megastructures (Rendezvous With Rama) or dramatising the unforgiving nature of orbital dynamics ('The Cold Equations'), is strung on a spine of actual or extrapolated science. But the pure quill of so-called hard sf quickly shades into fictions with more human concerns which respect the scientific spirit but have a focus that's elsewhere. That may be more interested in changes in society driven by science and technology, and the moral dilemmas those changes create, than in the actual science. And that in turn shades into the kind of sf in which science, or the vocabulary of science, or science's angle of attack, is used to illustrate a moral dilemma or some aspect of the human condition present in the actual world. The kind of story that has begun to dominate the Hugo Awards; the kind of story that this year's iteration of the Sad Puppy group railed against. John Cho's 'The Water That Falls on You from Nowhere', for instance, or Rachel Swirsky's 'If You were a Dinosaur, My Love'. Humanist stories that appear to be the antithesis of hard sf, yet in fact respect the scientific rational and central importance of science in our culture as much as the purest, hardest hard sf. Stories that, like hard sf stories, are informed by the time in which they were written, for although scientific verities secured by empiric evidence may be immutable, the culture of science, because it's a human construct, is not.There's no us v. them. No central core that must be defended from impure outsiders. It's a continuum.