Sci-fi, given its grounding in science, makes the implausible possible. Fantasy, which has no grounding in reality, makes the impossible plausible.
In recent years that delimitation has grown increasingly blurred. Sci-fi has crossed the threshold into the realm of mysticism, territory that was once the sole province of fantasy. Star Wars is a readily identifiable example. Unquestionably rooted in science fiction, the use of the Force and the magic-like properties it bestows upon the Jedi (and Sith) practitioners encroaches upon the stock fantasy themes of wizards and spellcasting. Dune is another case in point. Ostensibly written as hardcore sci-fi, the prescient abilities of Paul Atreides and the Guild Navigators borders on the supernatural. And what of Stephen Baxter, Britain’s quintessential master of nuts and bolts sci-fi? His Mammoth trilogy and exceptional standalone novel Evolution cannot be considered as wholly one genre or the other, but a workable blend of both.
The science fantasy label bridges that gap. For me, it encompasses the best of both worlds. Magic and machinery coexist in mutual harmony. A prime example of this can be found in my Chosen Trilogy. How else could I place prehistoric life and extraterrestrials believably in the same setting, melding the disparate concepts of evolution and technology?
No doubt others will disagree with my assessment and seek to preserve the status quo. Naturally, there will always be a place in the literary world for traditional science fiction and fantasy tales. My own new series, Terrath, might be construed upon first inspection as typical fantasy fare. But threaded throughout the unfolding plots are mechanical wonders inspired by the sciences. Therefore, it is neither one genre nor the other, but a fulfilling amalgamation that enhances the storytelling.
Consider this parting thought that, in my humble opinion, sums up matters nicely:
Science fantasy is the child sired by Father Science and birthed by Mother Fantasy.