Frankenstein Part II - The Creature's Reasons

"A frightful selfishness hurried me on, while my heart was poisoned with remorse." - The Creature, page 163.

I believe this quote is proof that the Creature was not evil by nature after all.  He confesses that the reasons he did what he did was because he became selfish of all of humanity, including Victor.  His envy and bitterness is what motivated him to kill and seek revenge.  Originally, he was kind, warm, and happy.  Humanity's hatefulness towards him and his inability to be loved by any other being is what temporarily changed him.  Therefore, I believe that if Victor had gone ahead and created the second monster, the Creature would have probably kept his promise and gone and lived away from mankind.  This theory is also supported by the fact that at the end of the novel, the Creature decided to kill himself.  He felt bad for what he did and realized that he acted unjustly.