Read the excerpt from act 4, scene 3, of The Tragedy of Julius Caesar.

CASSIUS. Hath Cassius lived
To be but mirth and laughter to his Brutus
When grief and blood ill-tempered vexeth him?

BRUTUS. When I spoke that, I was ill-tempered too.

CASSIUS. Do you confess so much? Give me your hand.

BRUTUS. And my heart too.

CASSIUS. O Brutus!

BRUTUS. What’s the matter?

CASSIUS. Have not you love enough to bear with me
When that rash humour which my mother gave me
Makes me forgetful?

BRUTUS. Yes, Cassius, and from henceforth,
When you are over-earnest with your Brutus,
He’ll think your mother chides, and leave you so.

How does the characterization in this passage connect to its central idea?