This page explains how ethos (authority figures), logos (logic and statistics) and pathos (emotion) can be used in persuasive essays

Ethos, Logos and Pathos

Persuading someone to change his or her view is almost always based on the use of three methods of persuasion: Ethos, Logos and Pathos.

Ethos is an appeal to authority. For instance, if I'm arguing the benefit of a new toothpaste, a dentist would carry authority because of his training and experience in the field.

Logos is a way to argue based on logic, statistics, facts and research. For instance, I may describe a study in which the new toothpaste reduced tooth decay in more patients than the old toothpaste. They would probably use the number of the people in the study because the study would be more convincing with 600 participants as opposed to 12.

Pathos appeals to people's emotions. If you want to avoid cavities and ugly yellowing teeth, you need to use this new toothpaste, would be the argument.

A good argument often combines elements such as these, appealing to emotion, quoting authorities and then backing up the argument with facts and statistics.