Famous quotes containing the words key and/or system:
“Every revolution was first a thought in one man’s mind, and when the same thought occurs in another man, it is the key to that era.”
—Ralph Waldo Emerson (1803–1882)
“Books are for the most part willfully and hastily written, as parts of a system to supply a want real or imagined.”
—Henry David Thoreau (1817–1862)