"The Atheist's Mass"

Thinking about the nature of gratitude, and the very different forms its expression can take, I started thinking about one of Balzac's most famous short stories, The Atheist's Mass. In it a student discovers that his notorious atheist of a professor, who often criticizes organized religion and the Catholic Church in particular, has for twenty years been paying for and attending Mass four times a year. Is the atheist a secret Catholic? When the student gets the story out of the professor, it turns out that that he is not, but that gratitude to a good man is a powerful thing. If you've never read it, it is worth reading; and it is in any case a good depiction of someone expressing sincere gratitude in a purely symbolic way.