The variety of colour in objects cannot be discerned at a great distance, excepting in those parts which are directly lighted up by the solar rays.

Nature is full of infinite causes that have never occurred in experience.

Who would believe that so small a space could contain the images of all the universe?

We must doubt the certainty of everything which passes through the senses, but how much more ought we to doubt things contrary to the senses, such as the existence of God and the soul.

Just as a well-filled day brings blessed sleep, so a well-employed life brings a blessed death.

The human foot is a masterpiece of engineering and a work of art.

I roamed the countryside searching for answers to things I did not understand. Why shells existed on the tops of mountains. How the various circles of water form around the spot which has been struck by a stone, and why a bird sustains itself in the air.