Brutus used ethics by pointing out that he is very loyal to Rome before before he is even loyal to his closest friends. His goal was to impress the commoners. Antony used very convincing characteristics in his speech to persuade his audience. His goal was to try to get the commoners to fully believe him and see who the real murder is and set a look out for them. Brutus uses ethic to by suggesting that anyone who opposes Caesar's murder must also oppose Rome and therefor hate his own Country.
Antony uses persuasion to win over the crowd, and he makes a promise to Brutus not to speak bad things about them as to killers and not give them away so he twisted his promise around so it can backfire on Brutus as the killer. Antony handled his appeal better by getting the crowd to change their minds and find the real killer.