For Nietzsche, European civilization has been in decline since Plato. For Heidegger, the rot set in even earlier, with the Pre-Socratics. It is widely held among secularists that the history of Western civilization between the rise of Christianity and the Enlightenment was a centuries-long dark age that stalled the scientific progress that had been initiated by the Greeks and only restarted with Bacon, Galileo, Descartes, and Co. Marxists tell us that the entire history of the human race is a history of one form of oppression supplanted by another. Feminists tell us that it is, above all, a history of men oppressing women. Multiculturalists tell us it is a history of the West oppressing the rest.
Other examples could be given. The idea that vast stretches of human history – centuries, even millennia – have been shrouded in moral and intellectual darkness is taken very seriously.
Except when that idea is given a conservative twist. When a conservative says that things have been getting worse since the 1960s, or since FDR, or since the Enlightenment, or (as Richard Weaver says in Ideas Have Consequences and as I argue in The Last Superstition) since William of Ockham, the very idea of a decades- or centuries-long decline is dismissed as inherently crackpot, the ravings of a misanthropic crank or misfit.
Why the double standard? Just asking, as they say.
(The obvious answer might seem to be that the developments bemoaned by conservatives are “progressive” ones, and thus couldn’t possibly mark a decline. Out of charity, though, I won’t put this answer into the mouth of the left-winger, since it is blatantly question-begging. Surely the lefty has a better answer. So what is it?)