G. K. Chesterton 
The Man Who Was Thursday [EPUB ebook] 

Gabriel Syme is recruited at Scotland Yard to a secret anti-anarchist police corps. Lucian Gregory, an anarchistic poet, lives in the suburb of Saffron Park. Syme meets him at a party and they debate the meaning of poetry. Gregory argues revolt is the basis of poetry. Syme demurs, insisting the essence of poetry is not revolution, but rather law. He antagonizes Gregory by asserting the most poetical of human creations is the timetable for the London Underground.