The Evening Standard reviews
Don DeLillo's Zero K.
Part two of the novel, much more readable, sees Jeff back in New York, turning down his father’s job offer, describing his changing relationship with a teacher, Emma, who has a strange son adopted from the Ukraine, Stak. They visit an art gallery displaying a single huge natural rock and Jeff quotes Heidegger: “Man alone exists. Rocks are, but they do not exist. Trees are, but they do not exist. Horses are, but they do not exist.”
"The proposition 'the human being exists' means: the human being is that
being whose Being is distinguished by an open standing that stands in the
unconcealedness of Being, proceeding from Being, in Being." MH, P 284