I desire the company of a man who could sympathise with me; whose eyes would reply to mine.
Walton writes these lines to his sister as he describes his loneliness during his voyage. Note that Walton is not actually alone during this time: he is surrounded by ship mates and sailors. What makes him feel lonely is that he feels nothing in common with these men due to their different social class and lack of education. Walton fantasizes about finding a friend who would share his interests and point of view, and with whom he would be able to feel at ease.
I had never yet seen a being resembling me, or who claimed any intercourse with me. What was I?
This quote is spoken by the monster as he tries to make sense of his identity and origin. Because of his traumatic experience of coming in to the world abandoned, alone, and confused, the monster has no one to help him or guide him. He also does not even recognize what he is, which makes him feel even more intensely isolated. With these lines, Shelley captures the importance of community and family for identity formation. Human infants come to understand their identity by being surrounded by other humans, but the monster has no one else like him.
Satan had his companions, fellow-devils, to admire and encourage him; but I am solitary and abhorred.
In these lines, the monster expresses the extreme cruelty of living a life of complete loneliness and isolation. Since he has read Milton’s Paradise Lost, the monster is familiar with the story of Satan, and he comments on how the figure who is usually viewed as the most extreme of evil was still not sentenced to live completely alone. The monster’s loneliness is particularly acute because he knows he will be rejected anytime he tries to reach out to anyone, since his size and appearance make him terrifying to human beings.