First, thanks for an increasingly rare thing here in Medium, an intellectually serious article on an important topic. If I may, though, I do think that whole debate misses the most important point, which is whether there can be knowledge that people can be required to accept as true/valid.
In cases of knowledge that people cannot verify for themselves that requires an appeal to a higher authority. In authoritarian nations the person(s) in the positions of highest authority in government tell people what they are required to accept as true. Democratic nations have relied on trust-mostly, people trusting 'experts' to know what is true — particularly, in scientific matters. In recent years that trust has been greatly eroded.
The problem goes back to the 'Enlightenment'. Those thinkers correctly recognized that justice requires universality: a universally valid understanding of what justice is. Without that, governance cannot avoid arbitrariness, which John Locke had correctly identified as injustice when it comes to human relations.
Enlightenment philosophers looked at science and saw that such knowledge was universally valid. For them, that followed from 'objectivity'. For the more abstract knowledge of what justice is they equated 'objective' with 'secular' (as opposed to sacral). For justice, they ended up reasoning from secular beliefs: believing in equality and an a priori Right to liberty. The result was the first ideology: Liberalism.
Those thinkers failed to recognize that secular beliefs are every bit as immaterial as sacral beliefs are, rendering any product of such reasoning, i.e., ideology, as non-rational as any theology is. The practical failings of Liberalism combined with a philosophical critique of the 'Enlightenment project' to undermine the validity of that — or any — ideology. (With today's 'populism' we are in a realm of politics based on personal power, not ideology — though 'populists' might make references to both ideology and theology to further their aims.)
Unfortunately, given the historical link between science and the 'Enlightenment', the demise of ideology undermined the authority of science. Fortunately, there is a fatal flaw in that reasoning.
It is the universality of knowledge within material existence that makes it authoritative, not 'objectivity'. Sure, people can express doubt about any such knowledge, but without an erroneous link between ideology and science the authority of science would not have suffered the loss of confidence it has suffered.
Even better, it so happens that I have discovered how a bit of universally verifiable knowledge within material existence can be used to replace Liberalism (as we have known it) for justly governing governance: people have no choice but to effect choices, i.e., choose among perceived alternatives and take action to bring that choice to fruition (which I got from Warren J. Samuels). That makes choosing integral to being human, which is the starting point for an ethic of justice to govern governance: a requirement for people to respect one another’s capacity to choose, thus recognizing one another as fellow humans, whereas to act otherwise is to deny in some way or to some extent their very humanness, which can only be ‘justified’ by an appeal to some immaterial truth (valid for all who believe it but no one else), which is legitimately rendered illegitimate by this ethic’s being located in whole — both its determinant and its referents — within material existence. Given our propensity to live together in groups, a need for governance is a material fact of human existence.
if curious: "Can't Get Any Simpler" (a "3 min read" here in Medium with links to more about this idea--with nothing I publish here behind the paywall)