Angels can fly because they take themselves lightly.

A bird is active, because a bird is soft. A stone is helpless, because a stone is hard. A stone must by its own nature go downwards, because hardness is weakness. The bird can of its nature go upwards, because fragility is force. In perfect force there is a kind of frivolity, an airiness that can maintain itself in the air.... Angels can fly because they take themselves lightly.

This his always been the instinct of Christendom.... [P]ride cannot rise to levity and levitation. Pride is the downward drag of all things into an easy solemnity. One 'settles down' into a sort of selfish seriousness; but one has to rise to a gay self-forgetfulness. A man 'falls' into a brown study; he reaches up at a blue sky. Seriousness is not a virtue.... It is really a natural trend or lapse into taking one's self gravely, because it is the easiest thing to do. It is much easier to write a good Times leading article than a good joke in Punch. For solemnity flows out of men naturally; but laughter is a leap. It is easy to be heavy: hard to be light. Satan fell by the force of gravity.

—G.K. Chesterton, Orthodoxy (1908)

"Good work is not done by 'humble' men."

Some egotism of this sort is inevitable, and I do not feel that it really needs justification. Good work is not done by 'humble' men. It is one of the first duties of a professor, for example, in any subject, to exaggerate a little both the importance of his subject and his own importance in it. A man who is always asking "Is what I do worth while?" and "Am I the right person to do it?" will always be ineffective himself and a discouragement to others. He must shut his eyes a little and think a little more of his subject and himself than they deserve. This is not too difficult: it is harder not to make his subject and himself ridiculous by shutting his eyes too tightly.

—G.H. Hardy, A Mathematician's Apology (1940)

'that ultimate outward and inward simplicity which enables the heart to see'

Today, anyone wishing to enter the Church of Jesus' Nativity in Bethlehem will find that the doorway five and a half meters high, through which emperors and caliphs used to enter the building, is now largely walled up. Only a low opening of one and a half meters has remained. The intention was probably to provide the church with better protection from attack, but above all to prevent people from entering God's house on horseback. Anyone wishing to enter the place of Jesus' birth has to bend down. It seems to me that a deeper truth is revealed here, which should touch our hearts on this holy night: if we want to find the God who appeared as a child, then we must dismount from the high horse of our "enlightened" reason. We must set aside our false certainties, our intellectual pride, which prevents us from recognizing God's closeness. We must follow the interior path of Saint Francis, the path leading to that ultimate outward and inward simplicity which enables the heart to see. We must bend down, spiritually we must as it were go on foot, in order to pass through the portal of faith and encounter the God who is so different from our prejudices and opinions, the God who conceals himself in the humility of a newborn baby.

—Pope Benedict XVI, homily on Christmas Eve 2011 (official Vatican translation, 2011)