“Blessed be all metrical rules that forbid automatic responses, force us to have second thoughts, free from the fetters of Self.” – W.H. Auden

Not sure of the provenance of this quote, but it was the epigraph of the book, On Grief and Reason, by Joseph Brodsky.

UPDATE –
This can be found in the section, Shorts II, in the COLLECTED POEMS:
COLLECTED POEMS
W.H. Auden