‘The Constitution of Shelley’s Poetry’ is a close philosophical reading of ‘Prometheus Unbound’ and other Shelley works from the perspective of the argument or drama of language played out in its pages. The book urges and practises close reading, but in the thought of Stanley Cavell, it finds and develops philosophical grounds for this ostensibly old-fashioned approach, and it implicitly proposes an understanding of language very different from those currently assumed in literary studies.