For me fantasy is generally mythic in nature. A hero or heroes who seek to redress some evil or imbalance. Typically a quest or journey must be undertaken, wars fought, villains defeated. These stories find their origins in our myths and legends like; Arthur, Perseus, Beowulf. Often in these stories there is a paranormal element; magic or mythical beasts, strange races and monsters. Fantasy also incorporates adventure stories, journeys into strange lands by adventurers seeking treasure and fame. Typically these stories are set in a fictional medieval or pre-industrial world.
What you could argue is that Fantasy is trying to create it's own mythology. Not the mythology of a culture, but instead the mythology of the writer and his reader. While some fantasy is directly inspired by historical cultural mythology, others tales are simply stories of the common man(or woman) and their place in the fictional world. This is commonly known as low fantasy, and I love it.
A very common theme of fantasy literature is the hero of seemingly humble origins whose family or home is destroyed, which is a catalyst for them to go on a quest to discover the secret of their greater destiny and destroy/overthrow an oppressive evil. usually with a mentor and a rag tag band of friends with skills and attributes to help them succeed.
Sound familiar? Of course it does, its Star Wars IV; A New Hope. Star wars as a story which follows mythic convention of a hero's journey. This does not make Star wars a fantasy story per say. But for me the inclusion of the Jedi knights does. The Jedi knights use a paranormal power known as the force. The hero's mystic mentor is a Jedi Knight who instructs him on his journey. Even the name Jedi Knight and their use of light sabres are fantasy elements. I believe Lucas took a fantasy story and did use science fiction as a setting, blending the two and in doing so created something new, but very familiar to his audience.
Genre purists have a great difficulty in movies that over lap genre styles and conventions. Mostly because they stick to rigid theories about what a narrative is, while forgetting that in most cases the creator is simply trying and exciting vehicle for his story.
But where does that lead us? Are they the same, or different?
For me I think that Fantasy is a distinct narrative style. It can have it's own conventions, and typically it's own setting. But also that there is room for the blurring of boundaries. Which is good. But while I think you could have a fantasy science fiction, I am not sure the reverse is true. While I could be wrong, can you inject science into a fantasy setting and have it retain what it is that makes it fantasy? Or would the science over power the fantasy elements and just make it a science fiction story?
That's my opinion anyway.
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