Quote by Jean d'Alembert

"Doubt is an uncomfortable condition, but certainty is a ridiculous one."

"The greatest mathematicians, like the greatest poets, are men of imagination."

"I believe in God, but I do not believe that God has any of the properties which theologians ascribe to him."

"The true method of knowledge is experiment."

"Gratitude makes life richer."

"A grateful heart is a happy heart."

"Respect those who came before us."

"Life's greatest treasures are the people we love"