One can classify science fiction, and speculative fiction more generally, along several dimensions. Here are some, courtesy of myself and various others:
Grading Science Fiction for Realism goes into gory detail about the first sort of hard vs. soft distinction, though it also includes worldbuilding coherence.
Star Trek is also on the optimistic side of the optimism-pessimism axis, and to some people, sometimes too optimistic.
- "Hard" (our world's behavior) -- "Soft" (a purely imaginary world's behavior)
- "Hard" (nuts-and-bolts, technology) -- "Soft" (psychology, sociology)
- Coherent world -- Incoherent world
- Optimism (utopian) -- Pessimism (dystopian)
Grading Science Fiction for Realism goes into gory detail about the first sort of hard vs. soft distinction, though it also includes worldbuilding coherence.
- Cutting-edge present-day technology, with some developments and speculations, but nothing big
- Ultra hard / diamond hard: plausible developments of current technologies
- Very hard: plausible developments of provocative contemporary ideas
- Plausibly hard: very speculative things
- Firm: very unrealistic or impossible things but used as little as possible
- Medium: more unrealistic things, though with good science, worldbuilding, and plotting
- Soft: lots of unscientific things, though with story consistency
- Very soft: even more unscientific things, though with less story consistency
- Mushy soft: grossly unscientific
- 2001: A Space Odyssey: ultra hard except for its monoliths and wormholes (firm)
- Isaac Asimov's Foundation series: firm
- Isaac Asimov's robot stories: ultra hard except for the positronic brains (firm)
- Frank Herbert's Dune: medium
- Babylon 5: soft
- Star Trek: very soft, though some of its better episodes are plain soft
- Star Wars: very soft
- Space:1999, Dr. Who: mushy soft
- Superheroes, anime giant robots, Godzilla and similar monsters: mushy soft
Star Trek is also on the optimistic side of the optimism-pessimism axis, and to some people, sometimes too optimistic.
