See Frankenstein #3

This book tells us that humans are inherently good, despite many of their actions.This is true from the beginning, when Frankenstein first creates the monster. He created the monster only to push the limits of science, not thinking at all what would come of it. His intentions were good. After creating the monster, he spent the rest of the book trying to fix what he had began. After each disaster, Frankenstein looks increasingly evil but his actions are just reactions to the many deaths in his family and his guilt that builds up. This does not mean that he is evil, though. An evil person would not feel guilty after going through what Victor had, and that was not the case. After losing Henry, Elizabeth, and his father, Frankenstein is at his lowest point. He vows to avenge his family's deaths: "..I will exert myself; and if it is in my power to seize the monster, be assured that he shall suffer punishment proportionate to his crimes"(148). This destructive mood is a result of his extreme guilt and even though he is consumed with hate for the monster, it doesn't define him. It doesn't make him inherently evil.
I agree with Shelly for the most part. There are exceptions to every rule, but generally, humans are inherently good. Often we act poorly in response to something and appear evil. Other times we look evil based on our beliefs. I believe that in each individual's mind, they believe they are doing the right thing, while to someone else that good thing could look awful. It is rare to find someone whose every intention is to destroy and cause pain. Even from the 1800s, I think Shelley had the right idea about humans.