In Shakespeare’s King Lear Act IV, the King asks Gloucester how he was so good at seeing “how this world goes?” And Gloucester, who was blind, answers:
“I see it feelingly.”
On ne voit bien qu’avec le cœur. L’essentiel est invisible pour les yeux.
One sees clearly only with the heart. What is essential is invisible to the eye
Antoine de Saint Exupéry, The Little Prince