The most effective form of rhetoric is ethos. Establishing credibility is the basis behind any essay. Without credibility there is no reason for the reader to take in anything that the author is saying, because the author would seem to have no right to be talking about the subject. This type of rhetoric isn't necessarily the most abundant in an essay or always the most apparent. Logos and pathos also help to establish ethos. Adding logic to a statement makes the author more credible and reliable because they are providing evidence to support their claim. Pathos sometimes draws in personal experience which can also add the credibility showing that the author is directly related to the topic.
In Into the Wild John Krakauer focuses mostly on pathos to make his point. By bringing in several outside sources to tell their sides of the story and their positive outlook on Chris, Krakauer is making the reader feel the same way about Chris. For example, Ron Franz in Chapter 6 explains how fond he is of Chris and how much he appreciates Chris sending him letters and visiting. These are examples of pathos because they show Ron's positive feelings towards Chris, giving the reader these positive emotions as their background for Chris's character.