No one who visits the Victoria and Albert Museum’s Room 50A will leave thinking the Middle Ages were backward
If you have any knowledge of European history you know that the idea of the Middle Ages being a cruel and backwards time is completely ridiculous. The science and culture that came from the period were astounding.
If anyone thinks that people in the Middle Ages were backwards, they need to see Chartes Cathedral, or any of the Gothic Cathedrals.
The Middle Ages were considered backward because of the loss of Classical learning in the West (particularly Greek and the great Greek philosophers) and the loss of a united Mediterranean region under Roman rule.
Thomas Aquinas would strongly disagree with you on the loss of Classical learning (I think you probably mean “training”) in the West.
Aquinas was writing shortly after the appearance of some of Aristotle’s works in Latin in the West. But even Aquinas had to read them in translation–no Greek. And most certainly no Hebrew by which to read the Old Testament.