Fortunately the books were written in the language, the elements of which I had acquired at the cottage; they consisted of Paradise Lost, a volume of Plutarch's Lives, and the Sorrows of Werter. The possession of these treasures gave me extreme delight; I now continually studied and exercised my mind upon these histories, whilst my friends were employed in their ordinary occupations.
I can hardly describe to you the effect of these books. They produced in me an infinity of new images and feelings, that sometimes raised me to ecstasy, but more frequently sunk me into the lowest dejection.
In this passage in Chapter 15, the creature’s discovery of John Milton’s Paradise Lost, Plutarch's Lives, and Johann Wolfgang von Goethe’s The Sorrows of Young Werther marks an important stage in his intellectual and moral development. These books provide him with stories of heroism, love, and morality (as well as evil and isolation), and they shape his understanding of humanity and his own place within it. His description of the books as “treasures” emphasizes how much he cherishes knowledge and views it as a means towards connecting with others. At the same time, he recognizes that all the characters he’s reading about are vastly different from him, and it hurts him deeply to realize that he’ll likely never be able to join the human world and form friendships, even though he’s desperate to do so.
Many times I considered Satan as the fitter emblem of my condition; for often, like him, when I viewed the bliss of my protectors, the bitter gall of envy rose within me.
Milton’s Paradise Lost is the book that has the most impact on the monster’s thinking. Here, in Chapter 15, he compares his experience to that of Satan, whom he therefore has sympathy for. Read more about this quote in Quotes by Character: The Monster.
I sickened as I read. 'Hateful day when I received life!' I exclaimed in agony. 'Accursed creator! Why did you form a monster so hideous that even you turned from me in disgust? God, in pity, made man beautiful and alluring, after his own image; but my form is a filthy type of yours, more horrid even from the very resemblance. Satan had his companions, fellow devils, to admire and encourage him, but I am solitary and abhorred.'
In this Chapter 15 passage, the creature’s discovery of Victor’s letters forces him to confront the painful fact that his maker rejected him at the very moment of his creation. He feels more isolated than ever, and questions why Victor made him so hideous and abhorrent, virtually guaranteeing that he would never know happiness or belonging. He claims that even Satan is less alone than him, emphasizing the extent of his suffering, and highlighting the fact that rejection and loneliness play a critical role in shaping the creature’s sense of self and his view of humanity.
Satan had his companions, fellow-devils, to admire and encourage him; but I am solitary and abhorred.
The monster continues with his extended comparison of himself to Satan after reading Milton’s Paradise Lost with this quote, which you can read more about in Quotes by Theme: The Effects of Isolation.