Very nearly every political movement since the late 18th century has its roots in the enlightenment, from American constitutionalism to the rational imperialism of Napoleon. It is hard to overstate its influence on every strand of modern political thought, from conservatism to socialism to liberalism. All built on this revelation: that facts matter more than faith, and reason is greater than fear.
The fascism of Italy, that spread like wildfire across Europe and then the rest of the world, was not built on the foundations of the enlightenment. It was instead a rejection of the values espoused by it, a direct reaction to reason and humanism. Fascism dictates that acting as one is more important than what is actually true, and that the truth dictated by those in power is supreme to any other, no matter what evidence might say. As Sartre said: “ have chosen hate because hate is a faith to them; at the outset they have chosen to devalue words and reasons.”
I recently finished reading Nothing is True and Everything is Possible by Peter Pomerantsev, a harrowing account of the post-Soviet media under Putin’s regime. He describes how the propaganda under Putin, like that of the Nazi Party and the Italian Fascists before it, works not by espousing a single version of the truth, but by undermining the very concept of truth. It calls into doubt all sources, until the public believes none, and instead sees all truth merely as an act of faith. Evidence is not of intrinsic worth in a such an environment, but is instead perceived to be a rhetorical tool like any other.