The authors of this blog are generally skeptical that governments have authority. Of course, this one post won't demonstrate they don't.
But here's an example in which it might seem obvious that governments have authority, but in fact, they don't.
Consider the problem of coordinating which side of the street to drive on. For the sake of argument, let's assume that the choice of driving on the left or the right is, at first glance, arbitrary. It turns out that neither way of driving is safer or more efficient. (If it turns out that driving on the left is 50x safer and 10x cheaper, then countries would be obligated to switch or choose that.) Imagine we're starting from year zero, and there is no convention at all. We have to pick a side.
It seems reasonable here to select some sort of coordination mechanism. If we had a government, it might just announce, "We selected the right side." Maybe everyone would be obligated to go along with that decision, because that solves the coordination problem. So it seems government has authority here.
But not so fast. Even in this case, what actually does the work is not the government issuing the decision, but the people choosing to follow the command/edict/law.
To show why: Imagine that immediately after the government said, "Everyone drive on the right," everyone instead spontaneously drove on the left, all the signs were placed for left-lane driving, and so on. Suppose the government tried to enforce right-side driving to no avail. Which side should you drive on? The left, obviously. If you drive on the right, you'll follow the law, but you will unjustly endanger others. If you drive on the left, you'll break the law--and good thing, because in this case, breaking the law is obligatory so as to avoid endangering others.
What matters in this case is whatever actually solves the coordination problem. If everyone happens to be driving on the left, then that's what you should do.