How does the author appeal ethos here?

How does new technology, ideas, and innovations affect society

Agood persuasive essay topic cannot be a. a fact b. debatable c. something somebody else has already written about

[he] let his gaze wander to the swirling water of the stream racing madly beneath his feet. a piece of dancing driftwood caught his attention and his eyes followed it down the current. how slowly it appeared to move! what a sluggish stream! what contrasting words are used to describe the stream in this passage?