The Seventh Seal (Bergman, 1957)
"I want to talk to you as openly as I can, but my heart is empty. The emptiness is a mirror turned towards my own face. I see myself in it, and I am filled with fear and disgust. Through my indifference to my fellow men, I have isolated myself from their company. Now I live in a world of phantoms. I am imprisoned in my dreams and fantasies."
In this scene the Knight gives his speech to a wall as if looking in a mirror. He sees emptiness because he is looking into nothing but stone, literally. The imprisonment is represented by the following shot with him caged in on the other side of the confessional. Death asks him why he is trying to prolong his life, and the Knight answers that he's trying to know god - to know for sure of his existence. We can see this illustrated in this third shot in which the crucified Jesus hangs over Death's shoulder. This image tells us that the Knight can not know god until he accepts death.
I love this scene in the movie.