What is the theme in The Rings of Saturn by W.G. Sebald?

Death, finalities, and endings are a continual theme of the book and is used overtly as in the discussion of Thomas Browne's works or subtly by his intimations of loss and creeping decay. The Theme of death is first fully made known by the author telling us of the event that sparked off the entire book; the death of a close friend. Afterwards we are led into a study inspired in part by the eighteenth century doctor, philosopher, and theologian Thomas Browne who believed that everything diminished and finally died.