How do the themes of alienation and performance relate to Miller's Death of a Salesman?
Consider Willy Lowman's quote, discussing how a man isn't an orange, where one eats the fruit and throws away the peel. Willy feels extremely used up and alone. He also tells his wife Linda that when he goes to Boston and other areas of New England, people laugh at him. Now, while some would call this paranoia, it could also be that others see him for who he is... a washed up, burnt out salesman from yesteryear.
There really isn't a place for Willy anymore. In a dog-eat-dog world, the person is less important than performance. He is fired from his job when Howard no longer sees him as productive. Willy's idea that because he helped Howard's father name him, Howard should give him job security is something unknown to Howard. He is a business man, and Willy simply isn't performing.
This is some of the clear Marxist thought that we find in the book, where the workers' struggle against the capitalist system is unjust. Miller (the author) suggests through this work that lack of attention to the individual person is likely to cause a person to feel alienated and no longer worthwhile.