Dave Armstrong has claimed that he affirms sola gratia, but the Council of Trent clearly affirms something other than sola gratia.
Why then does Dave Armstrong call himself a Roman Catholic apologist if he does not hold to/defend the teachings of Roman Catholic Ecumenical Councils?
I suggest there are three possibilities:
1) Dave really does deny sola gratia, but says he doesn't because he realizes that a denial of sola gratia is an indefensible position in the face of Scripture (if so, shame on him for being Jesuitical in his apologetic);
2) Dave really does hold to sola gratia, because he realizes Scripture teaches it (if so, good for him!) or because he realizes some of the Catholic fathers, councils, or doctors have taught (not the best reason, but ok), or as a carryover from his Protestant years (doubtful, but who knows) or for some other reason (who knows?); or
3) Dave thinks he holds to sola gratia, in essence because he does not understand the significance of sola in sola gratia (I think this is the most probable, but I'll let Dave provide his own explanation, if he so chooses.).
Let's be clear about two things:
Trent does deny sola gratia and Dave says he affirms sola gratia. Incidentally, Dave is not the only Roman Catholic so to affirm, and very few Roman Catholics are willing to explicitly deny sola gratia. But Trent did deny sola gratia, which is why it became one of the three, and later one of the five distinguishing "solas" (shouldn't that be solae?) of the Reformation.