Heart of Darkness is often described as an important influence upon and precursor to the literary movement of Modernism. The debt is perhaps confirmed by T. S. Eliot's use of this quotation as the epigraph to his 1925 poem ‘The Hollow Men’.
That Heart of Darkness had a special significance for Eliot can also be seen in references made to it in 'The Waste Land', as described in this note to the essay 'Notes on the Publishing History and Text of The Waste Land' (reproduced in The Waste Land Casebook Series, 1964):
In the first of the published letters between Pound and Eliot on the poem, Pound said, ‘I doubt if Conrad is weighty enough to stand the citation’ [...] Hugh Kenner ... learned from Eliot that Pound referred to Eliot’s quotation of ‘The horror! The horror!’ from Heart of Darkness. As Pound suggested, Eliot removed the quotation. But Pound apparently was unaware that the words in lines 268-70 of The Waste Land were derived from the first page of Heart of Darkness ... and that various passages in the poem concerning the Thames are strongly reminiscent of the first few pages of Conrad’s novel.
The lines from 'The Waste Land' referred to are from part III, the Fire Sermon:
The barges drift
With the turning tide
This would appear to be inspired by a passage from the second paragraph of Heart of Darkness: 'In the offing the sea and the sky were welded together without a joint, and in the luminous space the tanned sails of the barges drifting up with the tide seemed to stand still in red clusters of canvas sharply peaked, with gleams of varnished spirit.'