The distinctions I suggested yesterday aren’t prescriptions; they’re characterizations or descriptions. In the broad field of SF and fantasy literature, there are deep-seated conventions about whether a given story is SF or fantasy (or horror), depending on its topic. Many topics are obvious: Witches? Fantasy. Space travel? SF. Of course there are gray areas (and sometimes they are most interesting stories), but the vast majority of published novels and stories are easily categorizable.
Most of the items I list as ‘supernatural phenomena’, were they to be subjects of a story in the sf/f genres, would automatically classify their stories as fantasy. Ghosts, angels, witches, demons, gods. There are crossovers; SF that imagines ‘gods’ as non-supernatural beings; even SF that tries to justify ideas like souls or telepathy. And there’s fantasy that is rigorous, in a scientific manner, about how ‘rules of fantasy’ e.g. are manifest.
(I gather however that there various flavors of Christian fiction, and no doubt analogous traditions of literature in other cultures, that assume that guardian angels and demons, not to mention Jesus and God, are in fact real, but let’s not go there just now. Such genres have no overlap with the speculative genres of SF, fantasy, and horror.)
Again, not every ‘supernatural’ phenomenon in my list is automatically fantasy. SF has a long history of taking various ‘pseudo-scientific’ phenomena, such as telepathy and telekinesis, more or less seriously. The hardest of hard SF magazines in the 1950s, Astounding (renamed Analog in the 1960s), gained a rather perverse reputation for taking such notions very seriously, both in fiction and in ‘fact articles’. (Dianetics was one such hobbyhorse of editor John W. Campbell for some years, before L. Ron Hubbard re-named it scientology.)
And to this day, a certain strain of SF, especially movie and TV SF, routinely depicts various extrasensory powers, from Spock’s “mind meld” to Star Wars’ “force” [which it must be said is so flagrantly supernatural it qualifies the movies as fantasy], as givens in their futuristic settings.
Whether particular SF stories take such notions seriously might be a marker between ‘hard SF’ and more credulous ‘space opera’ strains (like Star Trek). There are many flavors of space opera, from those that are routine adventures translated into space, from those that are more rigorous yet presume the existence of, say, faster-than-light space travel, despite there currently being no plausible justification given our understanding of physics.
It would be interesting to collect some hard data, e.g. subjects of stories in anthologies explicitly labeled science fiction or fantasy, as evidence about what the community thinks is possible, or not.