يوسف بن تاشفين
"The book of moderation," this was a treatise on general therapy written in his youth for the Almoravid prince Ibrahim Yusuf ibn Tashfin. The book is a summary of various different diseases, therapeutics and general hygiene. It is also noted for its advice regarding cosmetics and physical beauty. Ibn Zuhr even recommended plastic surgery to alter acquired features such as big noses, thick lips or crooked teeth.