An incoherent mumbling of ice-floes

I'm in the midst of reading (very slowly!) Thomas Merton's Journal for 1939-41 and last night I found this sentence:

Then the Archbishop of Canterbury, smiling in his sleep, announces like the incoherent mumbling of ice-floes breaking up in the wastes of the Antarctic, 'You know Russia is gravitating back towards religion. The people will insensibly return to God because they have to.'

Wishful thinking then, wishful thinking by some on the right now. Merton was obviously not a fan of Cosmo Gordon Lang!