Energy/history

Famous quotes containing the words energy and/or history:

“The scholar may be sure that he writes the tougher truth for the calluses on his palms. They give firmness to the sentence. Indeed, the mind never makes a great and successful effort, without a corresponding energy of the body.”
—Henry David Thoreau (1817–1862)

“The history of all hitherto existing society is the history of class struggles.”
—Karl Marx (1818–1883)