I re-read segments of the preface to "The Liberal Imagination" by Lionel Trilling (1905-1975), in which he continued the admirable tendency of the Western tradition to be seriously self-critical (as opposed to dogmatic or postmodernistically ironic). Here is the passage

Mill, at odds with Coleridge all down the intellectual and political line, nevertheless urged all liberals to become acquainted with this powerful conservative mind. He said that the prayer of every true partisan of liberalism should be,

“Lord, enlighten thou our enemies. . . ; sharpen their wits, give acuteness to their perceptions and consecutiveness and clearness to their reasoning powers. We are in danger from their folly, not from their wisdom: their weakness is what fills us with apprehension, not their strength.”

What Mill meant, of course, was that the intellectual pressure which an opponent like Coleridge could exert would force liberals to examine their position for its weaknesses and complacencies.

Sadly, the only place on the web that appears to contain this quote is The New Criterion's review of The Betrayal of Liberalism by Hilton Kramer & Roger Kimball. The New Criterion, edited by Roger Kimball (!!) is a bastion of hacks defending Republican policy while trying to sound like conservatives defending the Western tradition. To be fair, the New Criterion does have a small share of intelligent articles and a large share of excellent poetry.