Cassius:
a peevish1 schoolboy, worthless of such honor,
joined with a masquer and a reveller2!

antony:
old cassius still!

octavius:
come, antony, away!
defiance, traitors, hurl we in your teeth.
if you dare fight today, come to the field.
if not, when you have stomachs3.

1. silly.
2. party goers.
3. the guts; the nerve.

how does this exchange contribute to shakespeare’s overall purpose in the tragedy of julius caesar?

powerful men are reduced to petty insults and violence.
powerful men are supportive of each others’ goals.
powerful men are interested in their countries be successful.
powerful men fight with rhetoric rather than with violence.