More from The Darkening Age: The Christian Destruction of the Classical World by Catherine Nixey

In such an atmosphere, it took something for a law to stand out as particularly repressive.

Yet one law did. Out of all the froth and fury that was being issued from the government at the time, one law would become infamous for the next 1,500 years.

Read this law and, in comparison to some of Justinian’s other edicts, it sounds almost underwhelming. Filed under the usual dull bureaucratic subheading, it is now known as “Law 1.11.10.2.” “Moreover,” it reads, “we forbid the teaching of any doctrine by those who labour under the insanity of paganism” so that they might not “corrupt the souls of their disciples.” The law goes on, adding a finicky detail or two about pay, but largely that is it.

Its consequences were formidable.

This was the law that forced [the philosopher] Damascius and his followers to leave Athens. It was this law that caused the Academy to close.

It was this law that led the English scholar Edward Gibbon to declare that the entirety of the barbarian invasions had been less damaging to Athenian philosophy than Christianity was.  

This law’s consequences were described more simply by later historians. It was from this moment, they said, that a Dark Age began to descend upon Europe.