He made the same conclusion, only less plainly revealed, few lines higher, not in blue.
So I took the blue text as: "I don't believe what i'm writing right now but if we all applied your line of thought I could use that as an argument".I don't particularly prescribe to the very American idea that an opinion's validity is not based on it correspondence to fact, but on the fact that it exists at all.
Since I don't even have that line of thought, he is arguing with himself.