Brutus vs himself- his loyalty and friendship to Caesar vs his own pride, ego, worries that Caesar as king will overthrow the republic.
I think the whole thing was the conspirators felt that Caesar was going to go nuts ruling Rome alone because before he killed Pompey Rome was ruled by a triumvirte. While Caesar didn't rule long enough for this to happen, the Conspirators killed him anyways. A good line to remeber when studying this play is "absolute power corrupts and power corrupts absolutely" [ Notso's advice column | Ask Notso A Question ]
Attention: NOTHING on this site may be reproduced in any fashion whatsoever without explicit consent (in writing) of the owner of said material, unless otherwise stated on the page where the content originated. Search engines are free to index and cache our content. Users who post their account names or personal information in their questions have no expectation of privacy beyond that point for anything they disclose. Questions are otherwise considered anonymous to the general public.