Eternal vigilance is the price of liberty.
Wendell Phillips, (1811-1884), abolitionist, orator and columnist for The Liberator
in a speech before the Massachusetts Antislavery Society in 1852, according to The Dictionary of Quotations edited by Bergen Evans
Fix reason firmly in her seat, and call to her tribunal every fact, every opinion. Question with boldness even the existence of a God; because, if there be one, he must more approve of the homage of reason, than that of blindfolded fear.
Thomas Jefferson (1743-1826)