When Victor realizes that he is going to die, he summons Walton to his bed and makes several significant points in his final speech. He tells Walton:
1. That he has let go of his feelings of vengeance toward the creature but he still believes that the creature needs to die so that he cannot harm anyone else.
2. He pleads insanity--really he does! After everything that has occurred, Victor states that he has examined his "past conduct" and that he believes he is blameless. He chalks up his creation of the monster to "a fit of enthusiastic madness" and then explains that his duty to his family and friends superceded any responsibility he should have had for his own creation.
3. He asks Walton once again, but this time out of "reason and virtue," to destroy the monster for him. While Victor believes that it is his duty to mankind to destroy him, he realizes that he is no longer physically capable of doing so.
4. Victor's final words to Walton demonstrate that he has gained some self-awareness. He advises Walton to
"seek happiness in tranquillity and avoid ambition, even if it be only the apparently innocent one of distinguishing yourself in science and discoveries" (Walton's September 12th letter to Margaret; pg. 205 in Holt Rinehart Winston edition of the novel).
These words prove that Victor recognizes the futility of the glory-seeking ambition of his youth.