Final answer:
During the Middle Ages, the Christian Bible and the Islamic Qur'an were the two most commonly referenced sources of knowledge, with monasteries and later cathedral schools and universities serving as centers for learning and preservation of texts.
Step-by-step explanation:
The two most popular referenced sources of knowledge during the Middle Ages were the Christian Bible and the Islamic Qur'an. These texts were central to the intellectual and religious life of the period, as they were the primary sources for teaching, scholarship, and religious practice.
Monasteries were the hubs of learning and book copying, preserving both Christian theology and classical Greek and Roman texts.
The rise of cathedral schools and universities in the late 11th and 12th centuries marked a shift in educational centers from monasteries to more urban settings, where philosophical discourse, particularly influenced by Aristotelian logic, flourished.
Additionally, Italian trade routes facilitated the recovery of lost Greek texts preserved by Arab scholars, a key factor in revitalizing medieval philosophy and contributing to the upcoming Renaissance.
The two most popular referenced sources of knowledge during the Middle Ages were manuscripts and the texts of ancient Greeks and Romans. Monasteries became major centers of learning, where monks painstakingly hand-copied books, including the Bible, commentaries, and classical writings.