Mary Shelley's Frankenstein, for some, exists as a warning to two very specific ideas. First, one should be wary of Forbidden Knowledge and the lengths one may pursue in order to surpass previous scientific advancement. Second, the novel serves as a warning about the power of nature.
First, and foremost, the novel serves as a warning against taking one's quest for Forbidden Knowledge too far. Given that Victor, after many trials, comes to reanimate life. Prior to his success, this has yet to be accomplished (or even attempted). Although Victor found success in his experiments, the true outcome of his success proved to be far more costly than the time he spent on his experiments. Instead of being something Victor could celebrate, he choose to alienate his creation, forcing his creation to take matters into his own hands. Without the nurturing care of a "parent," Victor's creation is unleashed on the world unrestrained. This, for Shelley, could show her disdain for things which get out of hand when in search of things which should be beyond mankind's grasp.
Power of Nature
One can certainly see the impact of Coleridge's "The Rime of the Ancient Mariner" on the novel. As detailed in the poem, the power of nature must always be recognized. As for the text, Shelley proves the power of nature in many ways. First, she proves the healing power of nature exists. For example, each time Victor succumbs to illness, it is nature which heals him. Second, the nature of the Creature proves to be far more powerful than his declared war against mankind. It is, essentially, in his nature to be compassionate and loving (which is unfortunately hidden (at times) by his behavior). Last but not least, nature proves to be the most powerful given the death of both Victor and the Creature. While nature has taken its tole on Victor's human body (during his pursuit of the Creature), the Creature gives himself over to nature. In the end, fire (a prominent part of nature and the story) rises over the Creature and his life.
I shall seek the most northern extremity of the globe; I shall collect my funeral pile and consume to ashes this miserable frame, that its remains may afford no light to any curious and unhallowed wretch who would create such another as I have been.
By the end of the novel, Shelley has made her warning obvious: never underestimate the power of nature and never overstep the bounds of mankind.
It seems to me that Mary Shelley's book Frankenstein, like other novels and stories with a similar theme, is not a warning about the misuse of science or about "hubris," but a direct attack on science itself. Frankenstein is called a Gothic novel, but it is also very much a sci-fi novel. It seems intended to warn readers that scientific investigation is a threat to mankind. The book was published at a time when science was beginning to call the Bible into question. Notably, scientists were asserting that the earth was billions of years old, rather than only some six thousand years old as stated in "Genesis." As science grew in influence, traditional religious belief was being undermined, and this conflict continues to our day. Frankenstein is one of many works of fiction which imply that scientific inquiry is potentially very dangerous by telling about a scientist who causes a disaster through his well-intentioned experiments. Victor Frankenstein is probably the prototype of all the so-called "mad scientists" who have appeared in the movies.
This repudiation of all science is implicit in Edgar Allan Poe's "Sonnet--To Science."
Who alterest all things with thy peering eyes.
Why preyest thou thus upon the poet's heart,
Vulture, whose wings are dull realities?
How should he love thee? or how deem thee wise,
Who wouldst not leave him in his wandering
To seek for treasure in the jewelled skies,
Albeit he soared with an undaunted wing?
Hast thou not dragged Diana from her car?
And driven the Hamadryad from the wood
To seek a shelter in some happier star?
Hast thou not torn the Naiad from her flood,
The Elfin from the green grass, and from me
The summer dream beneath the tamarind tree?