Victor's crime was trying to play God and create human life. Since he is not God, all of nature seems to symbolically fight him from the moment his creation opens its "dull yellow eye." No matter where Frankenstein goes to escape (and it is often in nature - the Alps, etc.) the monster is there. Even the cold, arctic works against him because the creature transcends nature and adapts to all conditions. While living out in nature (the forest), the monster teaches himself to talk, read and write, so this, too, acts against Victor. All nature seems to join forces to fight Victor's crime against it, the creation of the monster.
The monster is the biggest symbol of Victor's crime against nature, then. The monster himself tells Victor how he has suffered because of his creation - he is miserable because he has learned that he is sub-human, a beast that frightens everyone. He is ugly, huge and alone. The monster represents the ugliness of human pride because Victor created the monster out of a desire to become famous, to achieve recognition in his field of science. The monster kills everyone that Victor loves and in so doing, perpetuates Victor's crime of creating him in the first place. Victor's creation also becomes his undoing because the monster has made Victor's life as miserable as his own. Both Victor and the Monster travel all over the globe, one running away from his creation and the other running towards his creator. Nature has been perverted and it is a crime on many levels.
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