The odd thing was that before God closed in on me, I was in fact offered what now appears a moment of wholly free choice. In a sense, I was going up Headington Hill on the top of a bus. Without words and (I think) almost without images, a fact about myself was somehow presented to me. I became aware that I was holding something at bay, or shutting something out. Or, if you like, that I was wearing some stiff clothing, like corsets, or even a suit of armour, as if I were a lobster. I felt myself being, there and then, given a free choice. I could open the door or keep it shut; I could unbuckle the armour or keep it on. Neither choice was presented as a duty; no threat or promise was attached to either, though I knew that to open the door or to take off the corselet meant the incalculable. The choice appeared to be momentous but it was also strangely unemotional. I was moved by no desires or fears. In a sense I was not moved by anything. I chose to open, to unbuckle, to loosen the rein. I say, "I chose," yet it did not really seem possible to do the opposite. On the other hand, I was aware of no motives. You could argue that I was not a free agent, but I am more inclined to think that this came nearer to being a perfectly free act than most that I have ever done. Necessity may not be the opposite of freedom, and perhaps a man is most free when, instead of producing motives, he could only say, "I am what I do."
C.S. Lewis - Surprised by Joy (1955)