The skeptic is a natural conservative. He is so because a conservative is someone who abhors innovations and who views human society as something that simply cannot be improved by human reason. To him, society is a creation of thousands of years of history, of the designs of millions of individuals and is held together by the fabric of traditional social institutions that have emerged in the process of history. What can the puny human mind manage to do other than inadvertently tear asunder those institutions and leave society worse off. Michel de Montaigne, a diligent student of Pyrrhonian skepticism, expressed this opinion in his essay I:23 “On habit: and on never easily changing a traditional law”:
And here is one drawn from a different barrel: it is greatly to be doubted whether any obvious good can come from changing any traditional law whatever it may be, compared with the evil of changing it; for a polity is like a building made of diverse pieces interlocked together, joined in such a way that is impossible to move one without the whole structure feeling it. He who gave the Thurians their laws ordained that if any man wished to abolish an ancient one or establish a new one he should appear before the people with a rope round his neck, so that he could be hanged at once if anyone failed to approve of his novelty.
Of course, when I write of conservatives here, I do not mean “Conservative” in the sense it has in modern American politics, though there are certainly plenty of shared traits. Instead, I mean it in the most literal, and perhaps original, sense of someone who simply views conserving the institutional structure of society as the best policy. The skeptic in turn who takes seriously that all judgment is fallible and that relies on other means of justifying human behavior other than ratiocination like tradition (a famous example of this is Sextus Empiricus' reliance of traditional remedies rather than on reasoned inquiries into the nature of medicine in his own practice as a physician).
Unlike many modern aberrations popular among high schoolers and undergraduate, skepticism does not lead the skeptic away from traditions; instead, it drives them closer. Like the conservative, the skeptic's doubts about the powers of human reason leads them down the road of the traditionalist. That which is is for a reason and what better can we know? When a man comes forward with a innovation to society, the skeptic is then common partner with the conservative in wanting to hang him at once as a threat to society. As Montaigne said:
To speak frankly, it seems to me that there is a great deal of self-love and arrogance in judging so highly of your opinions that you are obliged to disturb the public peace in order to establish them, thereby introducing these many unavoidable evils and that horrifying moral corruption which, in matters of great importance, civil wars and political upheavals bring in their wake – introducing them moreover into your country.
Thus the skeptic becomes a conservative with the rallying cry: we have the society that we have been given by history, it is our job not to mess it up.
It is only once we are able to esteem human reason and to save some of it from the skeptic's critique that we are able to step away from a pure traditionalist conservatism and begin to think about stepping away from a historical fatalist notion of society. If Hume's approach to whittle down the claims of reason through philosophical critique were able to leave nothing left, then human reason would be incapable of comprehending the maze of chains of cause and effect that are necessary to comprehend to even critique social institutions. After all, if the human mind is going to be able to create a better course for the evolution of institutions than history, it must be able to understand how institutions affect human action and how they guide people to take certain actions.
Any critique must in turn also have a normative standard for how human beings ought to act and to create that standard human reasons must understand successful patterns of human action. Hence any argument against conservatism must be able to raise human reason above the critiques of skepticism and show that it can construct standards for reform that break from the historical evolution of human institutions. If that is ever going to succeed, then the skeptical arguments against reason must be beaten back.
That human beings so often critique them with the claims of reason is evidence that skepticism is more often an exercise in philosophy rather than a serious approach and that critiques of social institutions are so often successful in their aims is evidence that human reason can understand well enough the concatenation of events in society contra the claims of skepticism.