You'll find the quotes by Saint Augustine (Augustine of Hippo) in Quotes & Aphorisms.
When man speaks he can be observed by the movement of the limbs and listened to in his speech: but how can you penetrate his thought and how can you get to his heart? Who will ever understand what burdens he carries inside him. What really interests him, what he faces in his intimity, what he does or doesn't want?
And men go to contemplate the peaks of mountains, the vast billows of the sea, the vast currents of the rivers, the immensity of the ocean, the course of stars, and don't think about themselves.
You must mind two perils: from desperation with no escape and from unfounded hope.
Words weren't invented so that men could trick themselves but that they may pass on to each other the bliss of their thoughts.
Teach me kindness inspiring charity, teach me discipline giving me patience and teach me science enlightening my mind.