The notion of the middle ages as "the dark ages" is an invention of the Renaissance and was a self-conscious way for that period to define itself as a new flowering of culture. This is a Renaissance fiction not actually borne out by any attentive understanding of the Medieval world.
By the way, the Hellenic texts were preserved in Africa and the Middle East, translated into Syriac. When the Moors came out of Algeria into Spain, they brought these texts back into Europe - Dante, for example, seems to have not read Homer in the original although he places him in Limbo with the other Ancient Philosophers. What we know as Medieval culture, characterized by monasteries, universities and libraries in which Scholasticism thrived, was an internationalist global culture that fused Islamic, Christian and Jewish thought. The great library at Cordoba, Spain, founded by the Moors, was a centre of learning and brought together many traditions. The great thinkers of the Medieval period all shared key elements of a Neo-Platonic worldview, whether it be Aquinas, Averroes and Avicenna (Muslim scholars), Maimonedes (Jewish scholar) etc.
By the way, all of these thinkers argued that when science conflict with faith, faith must be considered an "open question" that must be reinterpreted (God cannot make 2+2=5). When we talk about Christianty today as "medieval" this is actually a misnomer, as the idea of strict adhesion to the Biblical word is a much later offshoot of Protestantism. All scholars in the Middle Ages understood the Bible to be written by way of analogy - a view shared by Koranic scholars as well - and that the Bible was required to be interpreted through science.
