Thomas discusses the old problem of how those born before Christ could be saved through faith in him. Thomas answer is a bit surprising, I have to say:
If, however, some were saved without receiving any revelation, they were not saved without faith in a Mediator, for, though they did not believe in Him explicitly, they did, nevertheless, have implicit faith through believing in Divine providence, since they believed that God would deliver mankind in whatever way was pleasing to Him, and according to the revelation of the Spirit to those who knew the truth, as stated in Job 35:11: ”Who teacheth us more than the beasts of the earth.”(II-II, Q2,7)
We can’t get around this by saying, yes that refers to the those living before Christ only, because the question Thomas is discussing is: ”Whether it is necessary for the salvation of all, that they should believe explicitly in the mystery of Christ?”. Of course Rahner knew his Aquinas very well, maybe he really was on to something?