Just as courage is the danger of life, so is fear its safeguard.

I love those who can smile in trouble, who can gather strength from distress, and grow brave by reflection. 'Tis the business of little minds to shrink, but they whose heart is firm, and whose conscience approves their conduct, will pursue their principles unto death.

The Book of the science of Mechanics must precede the Book of useful inventions.

Drawing is based upon perspective, which is nothing else than a thorough knowledge of the function of the eye.

Everything proceeds from everything else and everything becomes everything, and everything can be turned into everything else.

It is useful to constantly observe, note, and consider.

Fix your course on a star and you'll navigate any storm.