What is the most important quote from Act 4?

I like the metaphor of the worm in Act 4 sc 3. Everybody dies and the worm will eat of a beggar or a king. The worm becomes a metaphor for whatever it eats. the metaphor extends to the fish that eats the worm and the man who eats the fish.

Not where he eats, but where he is eaten. A certain

convocation of politic worms are e'en at him. Your worm is

your only emperor for diet: we fat all creatures else to fat us,