Seamus Heaney has had a distinguished career as a poet and a critic. His eighth volume of poetry, Seeing Things, appeared in 1991. Other major volumes of poetry have included Death of a Naturalist, North, Field Work, and Station Island. His critical writings have been collected in Preoccupations, The Government of the Tongue, and The Place of Writing. Heaney seems to be a poet in mid-career, moving away from an earth-centered poetry confident of its connections to a more-problematic region, where the poet becomes an uncertain pilgrim. As a critic, Heaney has high expectations for his own poetry and for that of other poets he admires, such as Lowell, Auden, Plath, Kavanagh, and Larkin. For Heaney, the most significant poets are those who have constantly challenged themselves to write 'ethical lyrics'. His own poetry responds to a similar challenge.