As Brutus, I am deeply troubled about the thoughts of killing Caesar. Caesar is my friend. I wish that he had not grown so ambitious. If only he had remained humble in his present position. Instead, he has grown power hungry. Cassius, I know you are leading me into dangers that I should avoid:

What dangers would you lead me into, Cassius,
That you want me to search for something
That I don’t have in myself?

I do not have it in me to kill just to be killing. Caesar has been my close friend, but I do fear that he desires to be king. I just know he is about to crown himself king and yes I do fear it:

What does this shouting mean? I’m afraid the people
Are going to choose Caesar for their king.

Cassius, I do fear it and I would not have it so. Therefore, I will listen to your plan. I am not sure I will go along with the plan, but I will listen. 

Yes, the more I meditate on Caesar's ambition, I know I must act to put a stop to Caesar's growing power. I must join the conspiracy even though it breaks my heart to do so. 

Caesar must be stopped. I cry tears as I have to kill him. Yes, I do have great emotional conflict in doing what has to be done. For his death I do mourn:

As Caesar loved me, I
weep for him; as he was fortunate, I rejoice at it; as he was
valiant, I honor him; but, as he was ambitious, I killed him.
There are tears for his love; joy for his fortune; honor for his
valor, and death for his ambition.

Although I loved Caesar, I love Rome more and for that reason, I had to kill Caesar:

Not that I loved Caesar less, but that I loved Rome
more. Would you rather Caesar were living, and you all die slaves, than
that Caesar were dead, so you all live freemen?

Surely, you all would rather live as free men. That is why I killed Caesar.