For one thing we know with certainty about the expert class is that they are never chastened. Their low-fat diet dogma simply and smoothly elides into a Mediterranean diet mantra (a diet, as it happens, with plenty of fats). Their demands that “safe” trans fats be substituted for saturated fats in processed foods simply transforms, 10 years later, into indignant demands that the trans fats be removed when it is discovered they are worse than saturated fats. The phrase “global warming” is simply dropped in favor of “climate change” when it is discovered that the planet actually has been cooling since the 1990s. In no case is there an acknowledgement that their prior expert pronouncements have been both arbitrary and wrong, and much less is there ever an apology. Being experts, and thus by definition correct, they never, ever have anything to apologize for. They simply abandon the old dogma as needed, and seamlessly adopt the new one.
For when you’re an expert within our multiplicity of institutions for public improvement, history will always have begun 10 minutes ago.