– Pliny the Younger
– Bertrand Russell, Sceptical Essays (1928), "Eastern and Western Ideals of Happiness"
– Frank Tibolt
– Confucius
– George Bernard Shaw
– Benjamin Franklin
– Cullen Hightower
– Alfred North Whitehead
– Luke Rhinehart
– Irish Proverb
– Samuel Johnson
– Henry Louis Mencken
– Thomas Hardy
– Anne Morrow Lindbergh
– Joseph Addison
– Arthur Guiterman
– Clarence Day
– The Talmud
– Jean De La Bruyere
– La Bruyere
– Lenore Hershey
– George Orwell
– Guicciardini
– Simeon Strunsky