A good, real, unrestrained, hearty laugh is a sort of glorified internal massage, performed rapidly and automatically. It manipulates and revitalizes corners and unexplored crannies of the system that are unresponsive to most other exercise methods. With the fearful strain that is on me night and day, if I did not laugh I should die.

Laughter can be used to sooth the mind and get rid of those awful thoughts.

Why don't you laugh? If I did not laugh I should die, and you need this medicine as much as I do.

Lincoln called laughter "the joyous, beautiful, universal evergreen of life."