He means "missing the obvious".
> circularities
He means being unable to define something in terms of its referents, instead defining it in terms of the properties you've already prescribed as being the thing. Can you define what love is without using terms like "affection"? Typically you need to start giving examples.
Overall he's using rhetoric to make fun of self-proclaimed intellectuals that can't, won't, or don't actually think.
> ensemble modulus linear aggregation
Sometimes, a collection of things is more than just the sum of its parts. I think his "minority rule" chapter was about how if you have a majority willing to make concessions and a minority unwilling to make concessions, the minority can control the actions of the majority. So their effect is more than the sum of their presence.
Trust me when I say he's intelligible. But it looks like his writing style is not for everyone.