To see what I'm saying, put "valid" for "rational". A flawed argument is no good, period; there's no such thing as a "mostly good" argument.
I'd probably go further and say that there's never been and never will be a significant argument that's purely rational.
The entire field of Mathematics.
Eventually the choice must be made on a value basis and values aren't rational.
Eventually the choice must be made on a value basis and values aren't rational.
That's true, but one's decision to go with paper or plastic is not an "argument".
is government socially valuable? I think the evidence for it is compelling but of course one can't know for sure.
Are you justified pushing other people around on a hunch?
It may be that, perhaps compelled by an evolved tendency toward hierarchy, people throughout recorded history have chosen to form governments even though it is bad for them but I doubt that.
You doubt it, but it happens to be precisely true. Observe that monkeys have hierarchy. It's hardly a human invention. A non-sentient being needs a herd instinct to survive, because cooperation is indeed necessary for survival.
One of the greatest social inventions, rule of law, requires government.
I'd be interested to see your proof of that.
People cannot effectively organize for their common defense against an organized enemy without government.
I'd also like to see the proof of that.
Simply having to debate policy rather than acting without thinking is valuable.
Without government, humans lose the power of reason and speech?
Why? The subject is rationality (def: based on reason), not validity and I think you must agree that the arguments and choices people make are rational to varying degrees.
I have responses yo your other points, but let's do it one at a time. Don't you agree that people make arguments and choices that aren't rational?