How does this Hamlet quote develop theme?
Give me leave. Here lies the water; good: here stands the
man; good: if the man go to this water and drown himself, it is,
will he, nill he, he goes,-mark you that: but if the water come
to him and drown him, he drowns not himself; argal, he that is
not guilty of his own death shortens not his own life.
(Gravedigger / Clown V,I, 14-20)
Most of the scene involving Hamlet's encounter with the gravedigger seems to have been written for comic relief. No doubt Shakespeare had at least one actor in his company who was good at playing comedy roles (someone with a funny face and funny manner like Bert Lahr in The Wizard of Oz. It could have been the same actor who played the drunken Porter in Macbeth. He might also have been assigned to play the role of the cobbler who appears in the opening scene of Julius Caesar. Shakespeare knew that his audiences wanted entertainment, diversion, and escape. He could have invented the part of the gravedigger solely to provide employment for one of the actors in his company, knowing that many of the people in his audience would enjoy the antics and mugging and malapropisms of the talented clown. It is probably a mistake to try to read too much into the passage you have quoted.