What are examples of ethos, logos, and pathos in Chapter 11 of The Life of Frederick Douglass?

Frederick Douglass uses all three modes of appeal in the first several paragraphs of Chapter XI of his Narrative.  He first appeals to logos--or logic--in the first paragraph when giving his reasons for not offering details about his escape:

My reasons for pursuing this course may be understood from the following: First, were I to give a minute statement of all the facts, it is not only possible, but quite probable, that others would thereby be involved in the most embarrassing difficulties.  Secondly, such a statement would most undoubtedly induce greater vigilance on the part of the slaveholders than has existed heretofore among them....

By quantifying his points by number ("First," "Secondly") Douglass makes his point in abstract, logical fashion.  Furthermore, he implies that, logically, were he to relate those details, he would embarrass some who helped him and hinder other slaves' escapes by increasing slaveholder "vigilance."

In the next paragraph, he relies on ethos--or his own authority as a speaker--to justify this decision:

I, however, can see very little good resulting from such a course, either to themselves or the slaves escaping; while, upon the other hand, I see and feel assured that those open declarations are a positive evil to the slaves remaining, who are seeking to escape.

Through repetition of the first person pronoun "I," Douglass makes clear that the only source of authority for both of these claims is himself alone.  Thus the reader has to believe that Douglass is speaking from a position on authority on these matters, as there is no other reason to believe his claims based on his rhetorical constructions.

Finally, Douglass' vision of a slaveholder in search of an escaped slave appeals to pathos--or emotion:

I would leave him to imagine himself surrounded by myriads of invisible tormentors, ever ready to snatch from his infernal grasp his trembling prey.  Let him be left to feel his way in the dark; let darkness commensurate with his crime hover over him....

The emphasis on feeling and imagination in the above passage indicates an emphasis on irrational faculties beyond reason and Douglass' authority.  Furthermore, using descriptive words like "infernal," "trembling," and "tormentors," works to elicit an emotional response (most likely of fear) on the part of the reader.  In the opening stages of Chapter XI, Douglass employs all three modes of appeal.