First, civilization ebbed and flowed until we got to the Renaissance and then the Enlightenment followed in short course by the Industrial Revolution. A tremendous amount of what we all count as civilization was formative during those great ages, from lasting philosophies to advanced mathematics, to artistic expression, to the age of invention. Now that's not to say the Orestia didn't precede, or the General Theory of Relativity didn't post date those accomplishments, they obviously did. The problem was that even in cases that major cultural or scientific advances did occur, they were mostly the result of a European-centric worldview. Of course there are notable exceptions, like Arabic numerals and gunpowder, but these are the exceptions that prove the general rule. Religious cannon is another exception to this list, as many cultures seem adept at producing provocative cultural traditions. No matter.
The whole of western civilization during the Enlightenment especially had as a goal that there are objective truths. Beauty means something. The "good" means something. Actions, results, and even a people's culture can be judged and adjudicated based upon that words mean something. And we know what they mean and can prove it.
Enter Post Modernism, stage left, which while at it's ascendency in the 1950-60s we are still living with today. Wikipedia defines it as
Postmodernism describes both an era and a broad movement that developed in the mid to late 20th century across philosophy, the arts, architecture, and criticism which marked a departure from modernism.[Ed Note, aka West Civ] While encompassing a broad range of ideas and projects, postmodernism is typically defined by an attitude of skepticism or distrust toward grand narratives, ideologies, and various tenets of Enlightenment rationality, including the existence of objective reality and absolute truth, as well as notions of rationality, human nature, and progress.
Harry Jaffa used to say that the heart of post-modernism was the proposition that the subjectivity of one’s convictions matters more than their objective validity, a more concise definition.
In any event, it was an attempt to replace most or all of western civilization with a more world-inclusive outlook. Doing so required repealing all objective truths, judgements about culture, and a host of common sense things because one couldn't negate the gains of western civilization nor could one create from whole cloth the lasting contributions of the !Kung for example.
Post modernism is to blame how we get insane comparisons between Wagner's Ring Cycle and the Blue Man Group. Or worse the performing of cliterectomies is something other than barbarism. Or English students demanding removing Shakespeare entirely from English departments.
From there it was a short jump to having objectively President Obama lying more than any other President in history to Candidate Trump lying more than any other candidate in history. There's your post-truth in a nut shell. Words don't matter. It matters which team you are on. Period. Full Stop.
I leave you with a recent academic abstract. Remember words don't matter any more:
Against influential strands of feminist theory, I argue that there is nothing essentialist or homogenising about the category ‘women’. I show that both intersectional claims that it is impossible to separate out the ‘woman part’ of women, and deconstructionist contentions that the category ‘women’ is a fiction, rest on untenable meta-theoretical assumptions. I posit that a more fruitful way of approaching this disputed category is to treat it as an abstraction. Drawing on the philosophical framework of critical realism I elucidate the nature of the vital and inevitable process of abstraction, as a means of finding a way out of the theoretical and methodological impasse that the ‘ban’ on the category ‘women’ has caused. Contrary to many contemporary feminist theorists, I contend that, although the category ‘women’ does not reflect the whole reality of concrete and particular women, it nevertheless refers to something real, namely the structural position as woman.
I think this means that “women” are real.