“Measure what is measurable, and make measurable what is not so”

“Measure what can be measured, and make measurable what cannot be measured.”

“It is surely harmful to souls to make it a heresy to believe what is proved.”

“My dear Kepler, what would you say of the learned here, who, replete with the pertinacity of the asp, have steadfastly refused to cast a glance through the telescope? What shall we make of this? Shall we laugh, or shall we cry?”

“E pur si muove."(And yet it moves.)(What Galileo purportedly muttered after torturers forced him to recant his theory that the earth orbits the sun.)”

“E pur si muove. (Albeit It does move.)[What Galileo purportedly muttered after torturers forced him to recant his theory that the earth orbits the sun.]”

“I have never met a man so ignorant that I couldn't learn something from him.”