As with other additions made by Mary Shelley in the early pages of her novel, this
renders more explicit the extent to which Victor Frankenstein and Robert Walton share
much the same passion for knowledge. Their seeming differences are really superficial,
accounted for by the terrible cost experience has wrought on Victor and the sheltered
innocence in which Walton has been protected. Mary Shelley here likewise strengthens
her plot line, giving Victor Frankenstein a strong reason for bestowing the terrible
moral of his autobiography upon the enthusiastic explorer, allowing him, too, to be
the first to indicate that he might be mad. By questioning Walton's sanity as well,
he opens up large problems of reliability that the subsequent narrative will exploit.