Ethos, Pathos and Logos are ways of convincing, which convince the audience. More often they call it three artistic proofs, and Aristotle coined these terms.
Ethos is used when it comes to attaining an ethical appeal, to convince the audience that the author has an ethical credibility source, and that he is worth listening. Ethos develops by selecting a words and language that is appropriate for the audience and the topic being discussed, working hard and being fair and impartial, giving the facts about expertise, achievement and pedigree.
Pathos means emotional attraction, and convinces the audience by appealing to their emotions. The author uses a pathos to invoke the emotions of the audience, wanting the audience to feel what the author feels. Pathos can influence the audience to feel pity or anger, depending on the author's needs and what he or she wants to achieve.
In this quote, the author uses a ethos, because his presentation of pedigree and expertise is obvious.