Anyone who invokes authors in discussion is not using his intelligence but his memory.

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.

Depth and strength of a human character are defined by its moral reserves.

The light and heat of the universe comes from the sun, and its cold and darkness from the withdrawal of the sun.

He who loves practice without theory is like the sailor who boards ship without a rudder and compass and never knows where he may cast.

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.

Lying on a feather mattress or quilt will not bring you renown.