Civilization is a product of canons. The Bible is a canon, and while the Iliad and Odyssey were not quite sacred scripture to the ancient Greeks, the Homeric epics went a long way toward establishing what it meant for a man or a city to be part of the Greek world. That world was almost a synonym for civilization itself. What was not Greek was barbarian.
What we have today as a canon of Roman classics consists largely of works that were considered essential to education, first in late antiquity and then in post-Roman and Renaissance Europe. The Aeneid was not written for schoolchildren, but for centuries they had to learn it. Early modern Europe was blessed to have not a singular canon but a compound one, with Scripture and religious works shaping Western civilization in tandem with the greatest surviving texts of Greek and Latin antiquity.
Europeans read lesser books as well, but the moral and intellectual foundations of a well-educated man of the West lay in the canon. And while the composition of the canon changed over the centuries, it had a reasonably stable core. This not only permitted Westerners from different counties or countries to discourse with one another about a common cultural literature but also allowed for conversations across centuries. Greek, Latin, and Hebrew were international and intergenerational languages in the early modern West. But even a humble playwright with “small Latin and less Greek,” as Shakespeare was described by Ben Jonson, could be familiar enough with the canon, in translation if not always in the original, to add his own masterpieces to its treasury.