Contemporary Western culture presumes to sit at the pinnacle of progress. It was not always so. The Greeks, those scions of reason and logic (who borrowed much from Egypt), believed that they lived in a period following a Golden Age of men and gods. A belief in progress as a linear march of history, with each successive generation building on the accomplishments of the last, is a relatively recent one.
It is easy to correlate this idea of progress with the material benefit of scientific empiricism since the early 19th century: the explosion of scientific discoveries of the last two centuries has been a blessing in helping elevate the standard living of Earthlings. I believe, though, that this easy correlation belies the growth in something equally (probably more) important and, conversely, nonmeasurable: the growth in the idea of liberty and the enormous impact of increasing the accuracy of prices which rises in proportion to free exchange.
Science benefited from the growing acceptance of liberty as an ultimate end as more and more scientists found opportunity in the greater availability of capital and the social and political freedom to pursue previously unacceptable ideas about how the world might work. Before Locke and Hobbes, Rousseau and Hume, Kant and Adam Smith, the Overton Window of acceptable discourse was framed primarily by religious considerations. The church did not object to an error in Galileo's thinking so much as object to his presumption of offering a more accurate view of the world than could the church. The church was the authority and the authority could not be wrong, which is to say: the church made a power play more than a good argument; a play that we still see being evoked today. Galileo had an empirical view; the church had a theoretical one. In this instance, the empirical view flowed from the Renaissance of Greek logic into the Enlightenment. Empiricism would come to frame the Overton Window for centuries.
Theoretical knowledge and the possibility of gaining understanding without experience (through apriori synthetic deduction) is an old idea. We see in early oral histories a transmission of a kind science in which past experience becomes a story with a moral or a lesson. These lessons helped human civilizations persist through calamity by nipping in the bud the consequences of repeatedly making errors in judgment. The theoretical code of the various churches presented various systems by which people could live in peace and prosperity. As an invention, religion codified the nonmeasurable truths of human interaction (or tried to). If you believe that stories have no real meaning in human history (you're wrong), then math is a good and old example of apriori theoretical knowledge.
That the epistemological bias of the church suppressed the work of Galileo is unequivocal. That the epistemological bias of contemporary politics suppresses the works of Mises, Hayek, Rothbard and Hoppe is contentious.
In discussing the political institutions today, the Overton Window encompasses how to use government, not whether we should use it. Few things remain free from the influence of the state today and it is rare that a situation that arises for which we find the consensus answer: wait before we act, it is likely that there are unseen forces acting as we speak to solve this problem before we make it worse. This is the pejorative, Partisan Gridlock, which impedes the bureaucrat from perfecting his fellow man.
Practical political discourse today evokes restlessness - a sense of needing to do something; in the future, perhaps we will swing back towards humility in the unseen hands of nature. As the discussion stands, communication is made all the more contentious by the unwillingness to acknowledge the current epistemological bias towards empiricism. Thus, the Overton Window will only accept ideas framed by this bias even when the outcome will likely aggravate rather than alleviate the problem.