It is the quietest and meekest people who are often capable of the most sudden and unexpected violences for the reason that when their control does snap, it goes entirely. (Hercule Poirot)
When a bishop at the first shot abandons the worship of Christ and rallies his flock round the altar of Mars, he may be acting patriotically... but that does not justify him in pretending...that Christ is, in effect, Mars.
Whether he's doing great acting or not, you're seeing somebody who is in the tradition of a great actor. What he does with it, that's something else, but he's got it all. The talent, the instrument is there, that's why he has endured.
If a writer stops observing he is finished. But he does not have to observe consciously nor think how it will be useful. Perhaps that would be true at the beginning. But later everything he sees goes into the great reserve of things he knows or has seen.