Proverbs 27:19

As in water face answereth to face - All men's hearts are pretty nearly alike; water is not more like to water, than one heart is to another. Or, as a man sees his face perfectly reflected by the water, when looking into it; so the wise and penetrating man sees generally what is in the heart of another by considering the general tenor of his words and actions.

"Surely, if each man saw another's heart

There would be no commerce; All would disperse, And live apart."

Hebert.