A martyr? who can say?

Robin Grove certainly is not convinced by Eliot's Thomas:

‘…he sweeps forward thourgh temptations progressively more inward, until the victory is gained…We know, because he says so. Or maybe, the doubt springs up, he has conformed God to his will, and chosen martyrdom vaingloriously after all.
There is simply no way anyone could tell. Whatever Becket’s motives, an audience can never be sure of them; only God can see his heart… Having directed us towards a light into which we cannot peer, the drama leaves un simultaneously exalted (God has given us ‘another Saint in Canterbury’) and pleasureably skeptical (the pious have been taken in by another holy fraud…).’

Perhaps the Knights are right after all? Whatever the case, Grove’s insight is that the true action of the drama, which is the nature of Thomas’ final choice and the divine verdict on it, has become ‘inaccessible to view’; and the spectators themselves become the subject of judgement by the play. Grove seems to find this turn to the audience quite unpleasant.

Robin Grove, "Pereira and After: The Cures of Eliot's Theatre " in The Cambridge Companion to T.S. Eliot, ed. Anthony David Moody, Cambridge Companions to Literature (Cambridge: Cambridge University Press, 1994), p. 170.