“I believe that the future of humanity is in the progress of reason through science. I believe that the pursuit of truth, through science, is the divine ideal which man should propose to himself.”

“I believe that all is illusion and vanity outside the treasure of truths slowly accumulated, and which will never again be lost. I believe that the sum of these truths, always increasing, will at l...”

“Keep well that is the half of wisdom and of happiness.”

“Up to this day, there has been no proof of the existence of any intelligence other than the human.”

“If you shut up truth, and bury it underground, it will but grow.”

“I am little concerned with beauty or perfection. I don't care for the great centuries. All I care about is life, struggle, intensity.”

“Even the Middle Ages, which condemned and punished animals in due form, was in this way much closer to them than we are. They held them to be guilty: which was a way of honoring them. We take them ...”

“The clearest way into the Universe is through a forest wilderness.”

“Until one has loved an animal, a part of one's soul remains unawakened.”