Any story whose premises contradict the rules of the mundane world can be defined as supernatural fiction, but a definition so broad would logically incorporate all categories of Fantasy, all nonmundane Horror, all Technofantasy and all Science Fantasy, and arguably all Science Fiction. It therefore makes sense to use the term more restrictively.
In SF the natural world is the base reality, and SFs take their argument from that base reality, even when they end by contradicting, transcending or teaching lessons to the base reality. SF is, therefore, more closely allied to science fiction than to fantasy. The supernatural world is other than the real world, and is generally seen as signalling Wrongness, though in much Occult Fantasy, and in revisionist versions of (in particular) the Vampire tale, the signals may be reversed, so that the supernatural world represents a higher rightness. The supernatural exists, therefore, in a contingent relationship to base reality, even though the relationship may be one of Parody. This contingency of the supernatural element distinguishes the form from the central line of 20th-century fantasy: High-Fantasy texts like J R R Tolkien's The Lord of the Rings (1954-1955) treat the Secondary World as effectively autonomous; Crosshatch texts like Lord Dunsany's The King of Elfland's Daughter (1924) similarly treat the Otherworld as existing in its own right; and even tales set primarily in the real world, like Thorne Smith's The Night Life of the Gods (1931), treat the fantastic as having a full, floating claim to independence.
Stories described as SFs – they begin historically with Gothic Fantasies and include Ghost Stories, stories of daemonic enthralment (see Dionysus; Pan), stories of the occult, Witchcraft tales, stories involving satanic rites or Pacts with the Devil, tales of Possession, vampire tales, Werewolf tales (and some other tales of Theriomorphy) and much Slick Fantasy – tend to invade or contradict the natural order to which they are ultimately bound. Usually narrated from a vantage-point situated in the real world, rather than from the vantage-point of the invading entity or influence, SFs generally reflect an initial disbelief in the incursion (or belief as a form of blasphemy), resistance to the violating supernatural element (or surrender to it, often sexual) or horror (or loathly wedlock). A sense of Wrongness pervades 20th-century fantasies when the secondary world or otherworld (or this world itself, in Fantasies of History and Instauration Fantasies) is threatened, often from within (see also Malign Sleeper, Thinning); in SF, on the other hand, wrongness accompanies threats to the real world from elsewhere, through incursions or wellings up of the supernatural. E F Bleiler, in The Guide to Supernatural Fiction (1983), prefers the term "contranatural" to supernatural; it is a term which clearly conveys this essential quality of violation.
Unlike fantasy, SFs tend to pay relatively little attention to Story, and certainly slight any conception of story as being a means of bringing attention to the Matter of the world – hence, perhaps, Michael Ende's use of a werewolf in The Neverending Story (1979) to tell the hero that beyond the protective realm of the secondary world he is a "neverending story" only in the sense that he is a lie. In fantasy, wrongness threatens the Story, and the successful telling (or finding, or recovery) of a Story almost invariably constitutes good news for the world (see Healing); to tell the Story is to welcome the outcome. The opposite is generally the case in SFs, whose plots tend to expose dreaded (or wrongly longed-for) anomalies which are violating the world and which must be expunged, cast out or wed; if an SF changes the world permanently, it is likely to be by means of a showdown Apocalypse.
Owing perhaps to the problematic relationship that tends to exist between the real world and the invading supernatural element, SFs very frequently incorporate ongoing arguments meant to explain the invading element, often in a tone of elect knowingness. In many SFs – not always deliberately – this didacticism about the supernatural creates an atmosphere of doubt. This irresolution is sometimes a blessing – many of the best ghost stories turn on arguments, often never resolved, as to whether or not the ghost is real (i.e., they are fantasies of Perception) – but overall the ontological insecurity of SF as a mode can easily vitiate the pleasure of the tale, however delectable the insecurity may sometimes be. In fantasy, mysteries may abound – but almost invariably within the frame of the tale. We may not understand what we have read, but we continue to read within a fantasy frame (see Fantasy; Tzvetan Todorov).
When the invasion of the mundane world comes together with explanations designed to justify or promulgate the principles underlying the invasion, SF tends to become a literature of seduction, at the level of either argument or action, or both. Like its close sibling, Horror – and increasingly so the more its subject matter resembles pure horror – SF is a literature concerned with the body, with violations of the body, with conversions and immurements and seductions of the body. Compared with (until recently) most fantasy, there is a large amount of Sex in SF, a sense that the relationship between the supernatural and the mundane may best be understood in terms of the minglings of flesh. In fantasy wrongness can often be identified as a threat to the Story; in SFs wrongness can often be identified as seduction with evil intent.
At the end of the 18th century, and for much of the 19th, SF was astonishingly popular; in The First Gothics (1987) Frederick S Frank (1935- ) estimates that as many as 5000 Gothic novels appeared between Horace Walpole's The Castle of Otranto (1764) and Charles Maturin's Melmoth the Wanderer (1820); of these, at least several hundred had supernatural elements. And, insofar as the Gothic novel serves as one of the central repositories of motif, location and plot for modern fantasy, SF itself can be seen as an essential incubator of the fully achieved 20th-century field – as the format through which Myth, Legend, Folklore, Fairytales and the literary Dream became available to the conscious fantasist.
As the 19th century progressed, SFs (mostly by this time ghost stories and tales of the occult) gradually began to separate itself from early works of fantasy by writers like Lewis Carroll and George MacDonald. Writers like Edgar Allan Poe, Nathaniel Hawthorne, Edward Bulwer-Lytton, Sheridan Le Fanu, E Nesbit (in her tales for adults) and Arthur Machen were essentially writers of SFs.
The most interesting 20th-century SFs have been defined – retroactively – as horror; but although that term may apply with some justice to the work of H P Lovecraft, it is more difficult to think of the ghost stories of M R James, E F Benson or Robert Aickman as readily understandable under that rubric. And, as the century progressed, it became increasingly difficult to give single labels to any writer of significance. Lovecraft himself must also be treated as a fantasy writer; and contemporary authors who have been justly associated with supernatural horror fiction – like Clive Barker, Stephen King and Peter Straub – are also creators of autonomous Secondary Worlds.
Indeed, it might be argued that SF – like the genre sf that flourished from 1925 to 1965 or so – has lost over recent decades any secure platform in an agreed reality. The world at the end of the 20th century may well incorporate too many futures – too many intersecting versions of what is real – for a fiction to flourish which depends upon a dominating relationship between the "real" world and other worlds contingent upon it. Where SF (with the exception of the ghost story) once tended to look upon the past with apprehension, it may be the case that Belatedness now defines the form, and has become its solace. [JC]