In Thom Gunn’s The Occasions of Poetry I came across this paragraph, which expresses that same incoherence that Eliot was grasping toward when he wrote of  ‘a raid on the inarticulate’ in his exquisite East Coker:

For me the act of writing is an exploration, a reaching out, an act of trusting search for the correct incantation that will return me certain feelings whenever I want them. And of course I have never completely succeeded in finding the correct incantations.

‘Incantation’ is very good, literally ‘singing spells.’ It calls to mind those rare occasions while reading when we come across an unerring incantation, a particularly resonant sentence or phrase that enchants us forever. Gunn writes of seeking transparency, of words being the glass to his mind, as though observing an object through that glass.