Dear Listers,
I knew I'd come upon the lines Mike had in mind -- sooner than later. Here they are, at last. I quote the passage from Eliot's "The Metaphysical Poets" that contextualizes them:
"Johnson, who employed the term 'metaphysical poets', apparently having Donne, Cleveland, and Cowley chiefly in mind, remarks of them that 'the most heterogeneous ideas are yoked by violence together'. The force of this impeachment lies in the failure of the conjunction, the fact that often the ideas are yoked but not united; and if we are to judge of styles of poetry by their abuse, enough examples may be found in Cleveland to justify Johnson's condemnation. But a degree of heterogeneity of material compelled into unity by the operation of the poet's mind is omnipresent in poetry. We need not select for illustration such a line as: 

     Notre ame est un trois-mats cherchant son Icarie;
we may find it in some of the best lines of Johnson himself (The Vanity of Human Wishes): 

     His fate was destined to a barren strand, 
     A petty fortress, and a dubious hand; 
     He left a name at which the world grew pale, 
     To point a moral, or adorn a tale.
where the effect is due to a contrast of ideas, different in degree but the same in principle, as that which Johnson mildly reprehended."

--- On Sat, 9/4/10, mikemail <[log in to unmask]> wrote:

I recently came across a copy of A Poem and a Vanity of Human Wishes by Johnson.  The introductory essay by TS Eliot 1930.  //Can someone direct me to the lines which Eliot considered an example of good poetry -the best ever written // - I have lost the reference which I took from the book.