Off hand, I don't recall. There is a moment at the end of the book where Ransom has a revelatory experience of all life in existence and understands it as an interlocking dance, something that doesn't fit either his theory of predestination nor free will.

Actually, looked up some quotes and found this:

The whole struggle was over, and yet there seemed to have been no moment of victory. You might say, if you liked, that the power of choice had been simply set aside and an inflexible destiny substituted for it. On the other hand, you might say he had delivered from the rhetoric of his passions and had emerged in unassailable freedom. Ransom could not for the life of him, see any difference between these two statements. Predestination and freedom were apparently identical. He could no longer see any meaning in the many arguments he had heard on the subject.