It was. But that turned out not to be tenable.
The problem was not reason itself...but that reason is actually a method, not a universal set of conclusions. Like any mechanism or method, it's only as good as the stuff you put into it.
What Modernism put into that "machine" was a set of assumptions that included things like, "The world is a purely rational place, subject to science in all aspects; what is not amenable to physical sciences is delusion," and "There is no objective thing called 'morality'; it's a mere sociological epiphenomenon or personal delusion that anything can be objectively right or wrong," and "Human beings are fit objects for scientific testing, management and manipulation for control." Later, they added, "The universe is a product of only time, chance and physical causes, and has no inherent meaning, direction or purpose." There were others, of course, but those were some fundamental ones. And since the raw product that was being "rationalized" was bad, the products that came out of the far end were also bad. But they were "rational," if the foundational assumptions of Modernism had been correct. They never were, however.
Meanwhile, Modernism turned out to be highly utopian. It believed, for example, in the Myth of Progress -- that is, that human beings are the products of a long process of evolution not merely in physical things, but also in moral ones; so all we have to do is cooperate with the progressive process, and things will continually get better. Sweet reason would conquer the world, and everybody would soon become scientific, orderly, well-managed, systematic, healthy, wealthy, technologically sophisticated and maybe even, one day, immortal.
What destroyed this delusion in actuality (if not yet in the minds of many Modernist ideologues) was WW1 and 2, especially; because in them, the Modernist skills of science and technology were bent to the pure project of producing as many corpses as possible by as many nasty means as could be devised, human sciences were turned to the task of mobilizing armies, and rationalization was employed to manage munitions factory productions and the train schedule to Auschwitz.
So much for the myth that modernization automatically produces moral betterment. That was the end of that.
Absolutely. And, of course, of the subsequent "Grievance Studies Affair" of Boghossian, Lindsay and Pluckrose. (I have their book on order, actually.) I totally loved what they did. I know that world, the world of academia, quite well...and they stuck a pin in a huge, pretentious balloon of nonsense, I would say.Are you familiar with the "Alan Sokal" affair? He was a scientist that got tired of pomo BS... fancy words that are put together in sentences devoid of meaning. So he wrote a piece of BS... literally, he intentionally wrote piece of garbage and submitted it to a pomo journal. Published. He was criticized for the effort and the pomo folk said "he didn't understand" (typical refrain) but I think he did prove a point.
Still, the problem with the term "Postmodernism,"is that as a term, it's actually huge and general. Some commenters actually trace its beginning back to things like the Pruitt-Igoe debacle in the mid '70s. But there was some hint of it earlier on, in the work of the Dadaists and Expressionists, or Kafka, or Kurt Schwitters and other interbellum artists and writers. Even back in the '20s, it was being seen that the so-called "Enlightenment Project" was producing some unexpectedly nasty fruit, and thoughtful people were beginning to criticize the mad dash toward Modernist goals.
So when we say something is "Postmodern," we could even be speaking of something from the 1920s, really. However, the full theorizing of Postmodernism seems to have been done in the '60s and '70s, so far as I can tell, and it really didn't enter the public imagination as a term until well into the 1990s, I think. And CRT, though it comes from the Frankfurt School of Horkheimer et al in the 1930s, didn't really get to its current size and influence until more recently, perhaps twenty years ago. Before then, it was one option, but not necessarily the controlling option in the universities, I would say. At least, that's how it went in my experience.
Postmodernism's complex. It's not really just one idea, but many, many ideas. They share in common a skepticism to practically everything (except the Postmodern narrative itself), and a critical view of Modernism. However, I don't think we beat Postmodernism by retreating into Modernism, because Postmodernism is actually right about some of the critical things it points out in which Modernism was clearly tragically failing. We don't want nothing but more mechanization, rationalization, sterilization, automation, centralized control, bureaucracy, conformity, environmental damage, dehumanization, objectification, manipulation, demoralization, mass management, and so on. They're ultimately pretty awful, and they're the fruit of Modernism.