“If, as Brian Aldiss contends, Frankenstein was the first true science fiction novel, it was also, appropriately enough, centrally concerned with the very dialectic that gave the mode birth. Whereas a fantasist of previous eras could have conjured the monster as a golem with an incantation or two and gone on to tell the same tale, Mary Shelley made her wizard a scientist and concocted a scientific rationale for the human creation of artificial life.
And if she invented science fiction, she invented something far more central than the mad scientist and the android. She shifted the responsibility for suspension of disbelief away from the reader and onto the writer.
She rationalized her mythic tale of wonder with the scientific world view of her day; in terms of literary technique, however questionable the scientific speculation might have been even then, she used a scientific rationale to persuade the reader that her story took place in the realm of the possible.
And that is as good a functional definition of science fiction as any—a literary technique for re-creating the lost innocence of fantasy, for resurrecting the reader’s true belief in the tale of wonder, in the possibility of the fantastic, in the notion that his universe and the universe of the marvelous may be one and the same. Through science fiction, via science and technology and not despite them, magic of a kind re-entered the mechanistic Victorian world, a magic that did not require the reader’s willing suspension of disbelief.”
– Norman Spinrad, “Inside, Outside” (From Science Fiction in the Real World, 1990)
Science channel documentary on Mary Shelley, which discusses Frankenstein in terms of contemporary scientific research: