Dear Charles,

Please check the URL below

https://en.m.wikipedia.org/wiki/Golden_age_of_Jewish_culture_in_Spain

Ben Gurion, the founder and first president of today's Israel made the same statement.

However, with the coming end of the Muslim/Arabic dynasty corruption and mess took over even among the Muslims themselves and worst during the expulsion period of the Arabs. 

But again, I believe in rather focusing on the same valued core of ethics and values so to bind and agree rather than separate and differ.