Europe went into a period of darkness by the time the School of Athens was closed by the Christian Emperor (advised by the Church). At this time, the philosophers were overwhelmingly Pagans who resisted Christianity - something the Church perceived as a threat. Around the time of Justinian I (530), a doctrine of extreme Christian religious orthodoxy had been fully consolidated. The Church, after taking hold of the Emperor and civil institutions, restricted that what was considered acceptable intellectual pursuit strictly to Christian orthodoxy. Christian monks systematically resorted to burning books of philosophy, considering them "works of demons".

Religious fanaticism caused by the Christian model of propaganda cultivated a climate of fear and terror "for heresy or demon worship" - which could apply to literally anything not sanctioned by the church. Even the common folk, not knowing any better, became suspicious of the intellectual pursuits of philosophers. During the reign of Justinian, no overt Pagan could expect a public career. Growing up to become a "famous thinker who discovered something" stopped being a viable life goal for aspiring curious children. The remaining philosophers fled to remote areas such as small Greek islands or further away in Syria and Asia Minor, and territory of the Islamic Caliphate where philosophical practise was (still) welcomed and embraced.

The Islamic world experienced an intellectual Golden Age while Europe was deep in the Dark Ages. While Europe was burning books, killing philosophers for heresy and destroying temples, Islamic rulers were proudly compiling and translating the works of the ancients, expanding upon them, while expanding their prosperous empire.

The Islamic Golden Age happened because initially, Islamic leaders were initially not religious fundamentalists. The rapidly-expanding Caliphate found in its wake plenty of libraries and worthy intellectuals (remnants of the Roman Empire), and they wisely chose to preserve and appreciate their value - giving birth to the famous Translation Movement. During some time, they even made learning of philosophy mandatory. This openness to open pursuit of knowledge lasted until Al-Mutawakkil denouced the study of philosophy, and lingered until Al-Qadir finally prohibited it, in favour of the literal interpretation of the Koran - which in turn brought about their own Dark Ages, which can be argued lasts until today.

Europe came out of a period of darkness thanks to the work of intellectuals who looked back at the work of the pagan philosophers. The Christian scholar Bernard of Chartres hence dared to coin the now famous phrase "standing on the shoulders of giants", talking of himself in his time: "We are like dwarves perched on the shoulders of giants [the Ancients], and thus we are able to see more and farther than the latter. And this is not at all because of the acuteness of our sight or the stature of our body, but because we are carried aloft and elevated by the magnitude of the giants."

The 3 periods of Renaissance pushed Europe out of the Dark Ages. In each of these, it is clear that the involved intellectuals were opening up to philosophy of the pagans again - studying Plato, Aristotle, and the writings of the Neoplatonic philosophers. The only difference was the Italian Renaissance, were an additional emphasis was placed on science and in the revival of the art styles of the Greco-Roman tradition.

Ironic as it may be, the Islamic Golden Age was intrumental in the intellectual revival of Europe - because their translations and the subsequent work they did upon the material ended up finding its way back to Europe - reawakening the lost knowledge of the old pagan philosophers, re-invigorated by the constribution of the Islamic scholars themselves.

Since Early Christians burned or banned all the writings of the philosophers they could find in southern and eastern Europe, Europe has much to thank the Islamic World for the Translation Movement, which played an integral part in preserving the writings of the ancients, making it possible to bring them back to Europe.

European leaders of the time obviously didn't fail to notice the Islamic Golden Age, and the rapid development it facilitated to their civilisation. During the time of the Islamic Golden Age, Europe was fractured, split into several petty Kingdoms while the prosperous Caliphate was a massive expanding Empire which eventually came knocking at their door, conquering all the way through the Iberian Peninsula, eventually reaching France - all this while their capital was all the way back in Baghdad!

The second most important event in the revival of European intellectualism is, in a dark irony, the Fall of Constantinople - the capital and last-standing city of the Roman Empire (yes they called themselves Romans, not Byzantines).

When the Eastern Roman Empire was reduced to one city and the final Turkish Ottoman invasion was imminent, a great exodus of intellectuals ensued - from Constantinople and neighbouring regions back to Italy in Europe. They brough with them not only their knowledge but many surviving texts of the pagan philosophers they had stored, as well as many art pieces, which inpired the Italians so much that it triggered the Italian Renaissance.

It is also crucial to highlight the role of the Merchant class in Italy to diminish the grip the Christian Church held in the institutions. During this time, thanks maily to the huge powers that Venice and Genoa had become, Italy was undergoing major economic flourishing.

This allowed for the dramatic improvement of the lifestyle and access to luxuries within Italy, and made people look less into the Church for solace and more to the Merchant class for prosperity, and all the good that came from economic growth, luxuries and art. Therefore in this period the Church largely conceded to the Merchants, and reluctantly lowered their grip on the institutions. After all, it was now evident that some agents of the Merchant class (like the Medici) held more real power than the pope himself. It can be said that there is a contemporary modern parallel to this - Elon Musk's aquisition of Twitter and the subsequent openness to free speech.