I am awfully glad Donald Hall (and not I) wrote this (from Their Ancient Glittering Eyes):
Eliot married poetry knowing that poetry was unstable. Because the form of poetry connects it to the crib, poetry is often the mother, and Eliot’s mother Charlotte was a poet. Vivien was as much unlike Eliot’s mother as could be, yet she was poetry. To marry the mother is at the same time wholly forbidden and wholly desirable. It is clear from Eliot’s poems that impotence, or at least sexual incompetence and coldness, obsessed him during his marriage to Vivien. Maybe Eliot married Vivien in order to be impotent, to suffer, and to write poems.