The Boundless Deep: Young Tennyson, Science and the Crisis of Belief

Shortlisted for the Baillie Gifford Prize for Non-Fiction 2025

What happens when a poet lives too long and becomes respectable?

Alfred, Lord Tennyson might provide one kind of answer; his reputation cast into deep shadow by the beard he sported in later life and his elevation to Poet Laureate during the high Victorian era, aged but 40. Before this, his cheek was clean-shaven and his poetry brimmed with radical ideas of science, challenges to belief and an imaginative response to the horrors of a godless universe.

From the prize-winning and bestselling biographer of Shelley and Coleridge, and author of the landmark, critically acclaimed The Age of Wonder, this is a book about the new science and scepticism of the 19th century; about ideas of geology and deep time, the vast beauty and the terror looming before all those who saw deeper into the stars and studied the new cosmology. Tennyson grew up amidst this turmoil, his imagination and intellect driven by the eruption of three new fundamentally transformative scientific ideas biological evolution, the notion of a godless, unpitying universe and of planetary extinction. These were as terrifying to Tennyson as climate catastrophe is to us today. They inspired him to grapple with ideas of his own destiny, the threat of suicide and depression, the struggle between love and loneliness, intellectual hope and spiritual despair.

As a young undergraduate, Tennyson wrote a 15 line sonnet The Kraken the sea monster of deep Time. A combination of ancient folklore and modern marine science, it was inspired by his lonely wanderings along the wild North sea beaches of Lincolnshire what he termed the spine-bone of the world. This monstrous creature becomes a vision or voice which rises out of the sea, out of the waves, out of the Godless deep.