History: from darkness to light?

From Darkness to Light (image by Imen Bouhajja, CC BY-SA 4.0)

One view of history, perhaps perverse, is to see much, if not most of human history as a picture of prejudice, myth and irrationality, which has only very recently, and even today only partially, been eradicated. The latest issue of the TLS is an example. The lead article is devoted to a book about the religious writings of Isaac Newton. It is well known that Newton was a religious fanatic, yet I was surprised at the Newton revealed here.

Equal parts litigator, millenarian, numerologist, moralist and paranoid conspiracy theorist … his clandestine, lifelong and almost entirely fruitless obsession with the subordinate status of Christ
(Oliver Moody, review of Priest of Nature: The religious worlds of Isaac Newton, TLS Feb 23 2018)

We are talking here about the man who is revered as one of the founders of modern mathematics, claimed by some to be the greatest scientist who ever lived. A few pages later, there is a study of several medieval historians. These writers, dating back some six or seven hundreds of years, display a vast array of blatant prejudice.

Clerical misogyny drove both Gervase of Canterbury and William of Newburgh to attribute the failure of the Second Crusade to a lack of chastity in the camps (Leon Craig, TLS Feb 23 2018, p10)

What nonsense is this? Are we supposed to take these historians seriously? And of course the medieval historians reveal rampant anti-Semitism, with references to the so-called blood libel. Perhaps we should be more surprised at any evidence at all of reasonable thought before the Enlightenment. The sheer otherness of earlier cultures is at times overwhelming. Did anyone ever think rationally?