2. Labor and man, man and labor, these are the parents of all truth. -Suhomlinski
3. The history of mankind is a history of continuous development from the realm of necessity to the realm of freedom. Mao Zedong
4. The body always ends in boredom. Nothing beautiful and interesting remains except thoughts, because thoughts are life. -Bernard Shaw
You can't find the truth on any serious problem without considerable independent efforts; Whoever is afraid of using kung fu will never find the truth. -Lenin