“And why don’t we know, now? “
Because those lovely barbarians known as “Mohammetans” burned the library of Alexandria.
And they’re still stuck in the third or sixth century.
Actually, Julius Caesar burned the library. The action of which you speak was trivial compared to that of Caesar.
That’s correct.
In fairness, almost all of what we know of classical Greek literature, mathematics and science is from translations and copies that came down to us from the Islamic University at Damascus. Arabic and Persian scholarship in the Middle Ages was of a very high standard, outstripping Europe by centuries. One side effect of the Crusades was to expose Europeans to their own intellectual heritage. To some extend Roman and Greek writings were seen as anti-Christian or at least in competition with Christianity during the "dark ages".
Today, it is the Islamists who are regressive and closed minded.
Well..., Much as I hate Islam, I have to confess that there was a little looting and burning by Romans and Christians before the Moslems finished the job.
But I'm sure that the mozlems would have burned it if they had had the chance.