A fascinating map of the history of science fiction reveals a complicated history, as well as a sharp line between the genres of fantasy and science fiction . Though the map is not complete (as if it could be!) it nonetheless provides a fascinating picture of the influences and schisms that exist in speculative fiction. Let us examine both.
The Influences of Science Fiction and Fantasy
It is interesting that the primary influences shown on fantasy and science fiction are fear and wonder (particularly related to religion), exploration, philosophy, art & social criticism, and exploration. In this particular scenario, a lot of ancestors of fantasy and science fiction are included, ranging from Marco Polo’s visit to China, the Medieval Jewish myths about the Golem, the socially critical art of Aristophanes and Dante, the philosophy of Plato, and the Bible are all part of the mix that created both science fiction and fantasy.
It is also interesting to note that both science fiction and fantasy are considered to be Western phenomena. Though the inspirations of both genre come from far and wide, including the Middle East, it is Western Europeans who are primarily given credit for the formation for creating both fantasy and science fiction literature, though other cultures (particularly the Japanese) are considered as being involved in it once they themselves came under the heavy cultural influence of the West .
The Crucial Divide
However, the map is even more interesting in its formulation of the critical divide that has (so-far permanently) kept science fiction and fantasy apart–the Enlightenment. On one side of the divide lies fantasy, crime and mystery novels, horror, westerns, and romances (though curiously enough romance in the form we know it as, a typically “fantasy” genre, is mostly ignored on this map). On the other side of the divide is space opera, hard and soft science fiction, cyberpunk, and so on. The map considers Narnia and the Space trilogy of C.S. Lewis  to be science fiction when its religious origins and disinterest in scientific explanations clearly make it fantasy. It is my guess that the philosophical interests of C.S. Lewis give it the “scientific heft” according to the maker of the map.
It is interesting that the divide seen by the mapmaker is so hard. If a clearly Christian fantasy author like C.S. Lewis can be considered as “science fiction” simply for including a rocket and being an author of obviously heavy philosophical heft, is the definition of fantasy and science fiction somewhat arbitrary in that we claim for ourselves influences that we want, and cast aside to the other side of the line those influences we do not wish to accept? In that case, our maps would tell us more about ourselves than about the genres we seek to describe.
A Personal Observation
Personally, though, I find a great deal of influences on my own writings from both sides of the line between fantasy and science fiction. Clearly, to anyone who has read this blog, I am deeply interested both in religion as well as science and technology. The two realms and the behavior of the humans in different fields is far more similar than distant. I too feel the pull of history as well as the wonder (and fear) about what may yet come in the future. This ambivalence between different inspirations and different emotions is itself part of the cauldron of items that we who write pick from when we engage in our own creative efforts. And yet many of us (myself included) are people whose works and musings cannot be easily put in a box, far too complicated for labels like “fantasy and science fiction,” no matter how much we may like to define ourselves and others so cleanly. It’s not necessarily a bad thing to be complicated, though, as it makes life and literature more interesting.