I'm not the best qualified to write a full appreciation of this amazing and prolific writer -- I've only read Bloodchild and Kindred. Still, I did find a quote from her that I'd like to share, from an article in MELUS. In an interview, someone asked her, "What good is science fiction to black people?" Her response was as follows:
What good is any form of literature to Black people? What good is science fiction's thinking about the present, the future, and the past? What good is its tendency to warn or to consider alternative ways of thinking and doing? What good is its examination of the possible effects of science and technology, or social organization and political direction? At its best, science fiction stimulates imagination and creativity. It gets reader and writer off the beaten track, off the narrow, narrow footpath of what "everyone" is saying, doing, thinking--whoever "everyone" happens to be this year. And what good is all this to Black people? ("Positive Obsession" 134-35)
In these rhetorical questions is a statement of her broad-minded mission. Octavia Butler was as ecumenical and progressive as they come, as far as the politics one finds embedded in her works. But she never used her writing to make narrow kinds of political arguments -- at least, not in the sense of the obvious rhetoric of race, gender, and sexuality that dominates our cultural debates. She either approached it eccentrically (time travel, blood lineage, and slavery in Kindred), or looked ahead a thousand years, to consider parasite/host (alien/human) eroticism. Her writing challenged and provoked all kinds of people, including those who weren't concerned about all the barriers she broke as a black woman sci-fi writer in a field dominated by heterosexual white men.
Incidentally, Octavia Butler is one of the rare sci-fi/speculative ficiton writers whose work really captivates readers who are themselves scientists. Here, for instance, is a biologist's response to the Xenogenesis trilogy.