The reference to "my day" for payment of "this duty of letters," enables
us to identify Donne's correspondent as Sir Henry Goodyer, to whom Donne
was in the habit of writing every Tuesday. (Cf. the first sentence of
XVIII.) When the present letter was written Donne was employed in
assisting Thomas Morton, Dean of Gloucester, and the leader of the
Anglican theologians in the all but interminable controversy with the
Jesuits which involved so many of the ablest churchmen of the period. The
"Apology" was probably Robert Parson's "confused and worthless work," the
_Treatise tending towards Mitigation_, in reply to which Sutcliffe
published his _Subversion_ in 1606, and Morton, two years later, his
_Preamble unto an Encounter_, which, happily belying its name, went far
toward closing the debate.