'If you would win a man to your cause, first convince him that you are his sincere friend.' - Abraham Lincoln
2300 years ago, Aristotle, in his Discourse on Rhetoric reduced the principles of argument to four major points.
1. WELL DISPOSE YOUR AUDIENCE TO YOU AND ILL DISPOSE THEM TO YOUR OPPONENT. - It is not enough to make your own case – you must be ready to deal with what other people say, particularly their most salient points. You may win the battle but lose the war through ignoring other peoples' arguments because you think your own is so powerful.
2. MAXIMISE YOUR SALIENT POINTS AND MINIMISE YOUR WEAKNESSES. - Develop a theme. Deal directly with the weaknesses in your argument before anyone can use them against you - don't ignore them.
3. REFRESH THE MEMORY OF YOUR AUDIENCE. - Napoleon Bonaparte said that only one device was needed to persuade - 'repetition, repetition and repetition'. Consistency and repetition are the hallmark of persuasive presentation - do it wise.
4. EXECUTE THE REQUIRED LEVEL OF EMOTION. - Do not be boring. Involve people. Do not allow them to be spectators. There is a place for emotion as a persuasive tool.