The previous post did a great job. I think it was really thorough. I would add to it by suggesting that the emotion of the failure brought about by freedom is another distinct reality in Shelley's work. One of the most compelling aspects of her writing is that in an age where human freedom was being extolled and seen as something that was nearly perfect in its own right, Shelley was able to raise a very Modernist condition present in suggesting that there is a certain pain of failure that is within the construct of human freedom. Victor would be one of the best examples of this. His faith in both science and his own freedom geared towards this end could not encompass the reality that his steps toward creation could encompass destruction, as well. It is this futility in freedom and the emotional desert that accompanies it that is something I find very striking in the novel.
At the heart of the horror of Mary Shelley's Frankenstein is not so much the terror felt toward the creature, but the terror of being unloved. For, the emotion of loneliness is central to the fear of the three major characters.
In his letters to his sister, Walton tells his sister of his loneliness. Although he is surrounded by crew members, he cannot find a kindred spirit among them:
You may deem me romantic, my dear siser, but I bitterly feel the want of a friend. I have no one near me, gentle yet courageous, ossessed of a cultivated as well as of a capacious mind, whose tastes are like my own, to approve or amend my plans.
Thus, the emptiness of the Artic through which he sails reflects the emptiness of his life. When Victor Frankenstein is taken on board, Walton feels great eagerness to communicate with him. But, sadly, Victor dies and Walton is not able to share his feelings with his new friend who is so despairing and melancholic.
While Victor Frankenstein does have a friend in Henry Clerval, it is not a friendship as defined by the Romantics in which feelings are shared and the intimacies of one's mind were revealed to the other friend. Victor remains intellectually remote with Henry, and this causes his isolation. This intellectual separateness of Victor is at the heart of his inability to relate to his creature, which effects the terrible loneliness of this creature as well as his own. Victor expresses gloom, misery, despair, melancholy in a Romantic fashion, but he never acts upon these expressions giving them action and reality. Thus, it is Victor's lack of emotional connection, his lack of feeling, that causes him to reject the creature he has created. This is the true terror, a terror caused by loneliness.
Separated and rejected by humanity, the creature portrays the horror of complete and utter isolation and its resulting loneliness. Posessing a loving heart, the creature is devastated by his alienation from humanity. For this reason, he vows to make himself deserving of this rejection by wreaking vengeance upon Victor's family and friend and by abandoning the emotions that have made him more human than his creator. In his murderous acts, he brings the terror of loneliness closer and closer to his creator, Victor. Yet, as Victor dies, the creature expresses his love for Victor, evincing his real humanity, his capability of being a friend in the Romantic definition, proving what the father, M. DeLacey tells the creature before the others enter:
"The heart of men, when unprejudiced by any obvious self-interest, are full of brotherly love and charity."
Certainly, one of the truths of Shelley's Frankenstein is the value of true emotion and its sharing with others. Without it, one risks the terror of loneliness and isolation.