Shakespeare, William. Julius Caesar

Many commentators note that the true “tragic hero” of the
play is Brutus.  He has the most lines, and he is the one confronted
with an impossible situation as he comes to see a conflict between his
political principles and commitment to Rome, on the one hand, and his
friendship and loyalty to Julius Caesar, on the other.  Choose a passage
where Brutus is reflecting on these conflicts and discuss.  What
important to him?  What is his mental world like?  His emotional life? 
What kind of a person is Brutus?