In his Empire of Liberty, Gordon Wood claims that:
Educated and reflective observers found it increasingly difficult to hold to the eighteenth-century conspiratorial notion that particular individuals were directly responsible for all that happened.... [W]ith the spread of scientific thinking about society many of these sorts of conspiratorial interpretations began to seem increasingly primitive and quaint.
But as Noemie Emery notes, such "conspiratorial notions" are alive and well, among our credentialed elites no less than anyone else, for "Some think their beliefs are so true and self-evident that principled and/or informed opposition to them is simply impossible, and that their opponents must be fools and/or villains. They also feel themselves under permanent siege, from the press, from the establishment, and most of all from the centrists in their parties."
Human nature 1, historicism 0.