The Muslims of Spain were also engineers who rivaled the Romans. Aqueducts in Cordoba brought drinkable water into the city, and Muslim scholars took the lead in agricultural science, improving yields on all kinds of new crops, allowing Spanish lives to be longer and less hungry. Everybody wanted to live in Spain. Even the greatest Jewish philosopher Maimonides wanted to live in Spain, but sadly he was expelled and ended up in Alexandria, Egypt. There he wrote his awesomely titled defensive rationality, A Guide for the Perplexed. I'm translating the title, of course, because the original text was written in Arabic. Meanwhile, China was having a golden age of its own.