Perspective is the most important element to possess in the act of learning. It allows one to see things as they truly are, and to perceive their big-picture significance. In a Christian context, the only way to improve one's sight is to make oneself more virtuous; this increases the grace that God bestows upon one. Once somebody's vision improves, he merits more of God's love. But keen vision must be combined with prudent judgment, based on distinguishing right from wrong. Those with proper judgment are concerned with practical and moral lessons, not just intellectual conundrums.
Of all the methods of learning dictated in the Divine Comedy – lecture and memorization, contrast, example, art, and sound judgment – Beatrice's lesson on proper vision is the most important
At the end of Paradiso, the unexpected disappearance and substitution of St. Bernard is not only a comment on Beatrice's worthiness to guide Dante this far, but is also Dante's way of refocusing readers' attention on the lesson of humility.