It is said that one day Khalifa Mamun, dreamed that a bald-headed man with a long beard, fair and ruddy complexion, broad forehead and joined-up eyebrows was sitting on a couch. In awe and with a trembling voice the Commander of the Faithful (i.e. the Khalifa) inquired: Who are you? "I am Aristotle" was the reply. Mamun then asked four questions:
1. What is good?
"That which is good by reason" was the reply.
2. What's next?
"Whatever is good by the law".
3. What's next?
"That which is considered good by the people".
4. And next?
Finally Aristotle advised Mamun to treat like gold whoever advised him about gold and to hold onto the doctrine of Tauhid (strict unity of God in Islam). It was the consequence of this dream, so the story goes, that Mamun decided to seek knowledge and for that purpose to accelerate the translations of the books of the ancient philosophers into Arabic.
P.S. Caliph al-Mamun (813-833) founded the House of Wisdom, the main scientific research center of the Arabo-Persian Golden Age (incorrectly called "Islamic Golden Age"). This golden age, which became possible due to a revival of Greek heritage, ended in the 13th century due to the rise of Islamofascists, who promoted bans on scientific knowledge, technology and innovation in general.