[The book] begins with a massively intricate philosophical joke involving a talking parrot. The bird, named Heidegger, is shrieking an obscene phrase as the novel's main character attempts to work on a manuscript.
The shrieked vulgarity is actually a garbled mistranslation of a line from the German Romantic poet Holderlin. The real Heidegger -- the philosopher, not the bird -- wrote a famous essay about the Holderlin poem in question, which is about, more or less, Meaning and Significance.
So the novel begins as Heidegger the Parrot garbles Holderlin the poet, as perhaps the real Heidegger the Philosopher garbles Holderlin the poet, and they are all misspeaking the nature of Humanness and the Transcendent.