Aristotle's 3 modes of persuasion: Pathos, Logos, Ethos

Pathos: "is an appeal to the authority or honesty of the speaker" 
Persuading by appealing to the readers emotions
             Subjective-using emotion
             Experience -> may happen
            
Logos: "describe facts and figures that support the speaker's topic"
(logic)    Factual information
             Academic situations, political, business, medical
             Objective-absence of emotion


Ethos: "is an appeal to the audience’s emotions"
The power of the speaker
Speaker-credibility-experience (own)


http://en.wikipedia.org/wiki/Modes_of_persuasion

Illinois Senate Candidate Barack Obama Speech Transcript

http://www.washingtonpost.com/wp-dyn/articles/A19751-2004Jul27.html


On behalf of the great state of Illinois crossroads of a nation, land of Lincoln, let me express my deep gratitude for the privilege of addressing this convention. Tonight is a particular honor for me because, let's face it, my presence on this stage is pretty unlikely.
My father was a foreign student, born and raised in a small village in Kenya. He grew up herding goats, went to school in a tin- roof shack. His father, my grandfather, was a cook, a domestic servant to the British.
But my grandfather had larger dreams for his son. Through hard work and perseverance my father got a scholarship to study in a magical place, America, that's shown as a beacon of freedom and opportunity to so many who had come before him.


In the speech made by Barack Obama for the US senate candidate has a strong sense of Ethos by relating to his own personal life and his own emotions for the audience to convince the responders that he would be a suitable choice for senate.