The Miser by Ingrid Jendrzejewski

The rich man gave generously to worthy causes, but then began to worry that he did it for less than noble reasons; he liked to see his name on buildings and to hear people say nice things about his family.  He decided to make his donations anonymously to see if that would help him feel more altruistic.  It worked for a while, but then he started to doubt himself again: he wondered if he was motivated not by a pure sense of charity but by the smug satisfaction he derived from imagining the gratitude of those he deigned to help.

In the end, he came to the conclusion that the only way to avoid selfishness was not to give away anything at all, so he cloistered himself away, shut his doors, cut his correspondence and ended his days stewing in his immense, selfless wealth.