I recently read a great article by Robert Fastiggi of Sacred Heart Major Seminary in Detroit. It is called Aquinas and Suarez on the Mediation of Pre-Lapsarian Grace through Christ.
At the end of the article he comes up with three conlcusions:
1) The traditional Thomist position of Journet which maintains that pre-lapsarian grace was not mediated through Christ is an inference which goes beyond the actual texts of Aquinas.
2) Suarez's position that pre-lapsarian grace is most likely mediated by Christ is a position that can be logically developed from the Summa of Aquinas and other sources.
3) The traditional Thomist view that the Incarnation was contingent on the fall is not supported by ST 2-2, 2.7 where Aquinas takes a position quite similar to that of Scotus. Indeed, we might say that----at least in this passage---Aquinas was a Scotist before Scotus.