When Robert Walton rescues Victor Frankenstein from the freezing Arctic waters, Frankenstein immediately faints and needs to be “re-animated” with a small amount of brandy (Shelley 26-7). Once he recovers, Walton takes care of him and treats him kindly even though “his eyes have generally an expression of wildness, even madness” and “he gnashes his teeth” (27). Walton is able to see “benevolence and sweetness” (27) in him and begins to “love him as a brother” (28), even though he barely knows him at all.
In contrast, when Frankenstein gives life to his creation, he is immediately horrified and abandons it in his laboratory (58). He is disgusted by the creation’s physical appearance, even though he picked each piece of it himself (58). He doesn’t even try to talk to or understand the thing to whom he has given life. In fact, the creature opens his mouth and may have been trying to talk to him, but he is not listening (59).
It could be that once a person has, like Frankenstein, attained the unthinkable and unnatural — the sublime — they are unable to reconcile with their own humanity. By laboring obsessively and neglecting correspondence with his family (55-7) Frankenstein has become alienated from humanity and become purely a vessel for science. Frankenstein refers to this state as a madness (29), and attempts to prevent Walton from pursuing a similar path of passionate scientific endeavor (29).
Frankenstein perceives himself as having created something monstrous which originally seemed only beautiful until he reflected on his work (58). This is all too apt a metaphor for the life he has created for himself over the 2 years he obsessed over his re-animation project. When Frankenstein says that “breathless horror and disgust filled [his] heart,” this is as a result of his deprivation of rest and health (58). He has become a monster in his narrow-sightedness and is desperately trying to stop the creation of another monster (of Robert Walton) by relaying his tragic story.