Anarchism is to Political Philosophy as Skepticism is to Epistemology

In Nicole Hassoun's NDPR review of Roderick T. Long and Tibor R. Machan (eds.), Anarchism/Minarchism: Is a Government Part of a Free Country?, Ashgate, 2008, we read:

Anarchism should be of interest [to social liberals] because it plays the role in political philosophy that skepticism plays in epistemology -- raising the question of what, if anything, could justify a state in the way that brains in vats, etc. raise the question of what, if anything, could justify beliefs. The debate between anarchists and libertarians should be of interest because if the anarchists are right then libertarianism commits one to anarchism. So, social liberals who take libertarianism seriously may have to take anarchism seriously too.

I was struck by the notion that anarchism is as it were political philosophy's skepticism.  A fruitful analogy.  The anarchist is skeptical about the moral justifiability of the state in the way in which the epistemological skeptic is skeptical about whether what we take to be knowledge really is knowledge.  There is a strong temptation, one I feel, to revert to a double insistence: first, that we have knowledge of the external world whether or not we can answer every conceivable objection to the possibility of such knowledge; and second, that some states are morally justified whether or not we we can explain to everyone's statisfaction what it is that confers moral justifiability on them.

Perhaps the right atitude is as follows.  Provisionally, we should just accept that some beliefs about the external world amount to knowledge and that some states are morally justified.  Ultimately, however, this is not a philosophically satisfactory attitude.  One wants rational insight in both cases.  And so we should keep working on the problems.  But lacking as we do proof of the impossibility of knowledge and of the moral unjustifiability of the state, we have no good reason to abandon our commonsense views about the existence of knowledge and the moral justifiability of some states.  You cannot be a philosopher without being a procedural skeptic; but if your skepticism hardens into dogmatic denial of the commonsensical, then the burden of proof is on you.