Read this excerpt from Endgame by Samuel Beckett:
HAMM:
I've made you suffer too much.
(Pause.)
Haven't I?
CLOV:
It's not that.
HAMM:
I haven't made you suffer too much?
CLOV:
Yes!
HAMM (relieved):
Ah, you gave me a fright!
(Pause. Coldly)
Forgive me.
(Pause. Louder.)
I said, Forgive me.
CLOV:
I heard you.
What thematic idea does this passage most clearly help develop?