Renaissance was possible thanks to the recovery of Roman and Greek literature by scholars of that time. Latin was also used that time but it was more academic and monkish.
Upon revisiting Latin texts in a more secular view people began to shift their consciousness and appreciate ancient culture. They thought they were alike in a worldly sense. They believed they had the same delicacy over important matters and they both believed in the humanities power to tackle everything. Then they started to study Greek which inspired Romans. The Greek manusicripts were present in Italy because during the fall of Constantinople many Christian scholars fled to Rome. They brought tales of Homer and many other important books.
This spur philosophical inquires. These maniscruptures made people start thinking about virtues of the human soul. They were also interested in the usage of language an its effects itself. Historian Bruni once said “knowledge alone is not enough, we must add the power of expression to make effectual use of what we know” implying rhetoric. Ancient writings had an other function too.
They offered practical teachings about life. They consisted of not theological but moral grounds with given answers secular in nature. This was in its most basic, a belief in the identity of the human spirit under its all epiphanies. They found that in classical texts there existed an ideal of human life, both moral and intellectual, by which they can profit now.