Reason With This Quiz on the Enlightenment

British philosopher John Locke’s “Two Treatises of Government” (1689) argued that a ruler only achieved authority through the consent of the people. This then made it essential for the government to protect the people’s fundamental right to life, liberty, and property. Thomas Jefferson was hugely influenced by Locke’s ideas when drafting the Declaration of Independence.

French philosopher Rene Descartes was one of the early drivers of enlightened thinking. His famous maxim essentially encourages people not to believe anything without first examining why you believe it. This was known as “Cartesian doubt,” a practice that encouraged skepticism and was instrumental in the development of the modern scientific method.

Scottish philosopher Adam Smith published his hugely influential tome “An Inquiry Into the Nature and Causes of the Wealth of Nations” in 1776. The book was the first major work on political economy, and today Smith is considered the “Father of Economics.” Smith argued against regulation of trade, instead believing that free enterprise would ultimately bring economic benefit to everyone.

Paine’s 47-page pamphlet “Common Sense” was first published in Philadelphia in 1776. In it, the English-born American philosopher not only argued against the monarchy but also boldly suggested America had an opportunity to find a new way to govern based on the principles of freedom and democracy. The pamphlet was hugely popular and influential, selling over 500,000 copies and helping to foment revolution.

The Russian ruler Catherine I was very intellectually curious and wanted to bring European ideas to Russia, so she began writing to French philosopher Voltaire. The pair corresponded for many years, sharing ideas on everything from war to the design of English gardens. Voltaire admired Catherine’s method of leadership as an “enlightened despot” and called her the “Star of the North.”

Natural philosophy is the study of nature, the universe, and natural bodies. It has been known as a concept since the philosopher Aristotle first used the term in ancient Greece, but it came to have a more dynamic meaning during the Enlightenment. Isaac Newton and Robert Boyle led the way, adopting a more systematic, evidence-based approach to their experiments on the world around them, and laying the foundations for modern science.

Benjamin Franklin’s experiments with electricity caught the public's imagination and helped to popularize scientific investigation. Franklin was fascinated by electricity, which at that time was little understood, and he conducted numerous experiments. In 1752, he flew a kite in the middle of a thunderstorm and collected ambient electrical charge in a jar to prove the link between lightning and electricity.

Discontent in France had long been brewing over the power held by the absolute monarchy and the oppressive feudal system. Enlightenment thinkers such as Jean-Jacques Rousseau and Denis Diderot encouraged egalitarian freedoms instead. On July 14, 1789, Parisian revolutionaries stormed the Bastille prison, a hated symbol of the French king’s tyranny, heralding the start of the revolution.

Isaac Newton was a physicist and mathematician who is considered one of the great minds of the Enlightenment’s scientific revolution. His work on the laws of motion and gravity, published in his 1687 book “Philosophiae Naturalis Principia Mathematica” (“Mathematical Principles of Natural Philosophy”), laid the foundations for modern physics.

The Enlightenment spanned from the late 17th century to the early 19th century, and was a period when rational thought and reason came to the forefront in Europe. Philosophers, scientists, and politicians moved away from traditional modes of thought and toward rigorous evidence-based ideas. The Enlightenment, with its emphasis on individuality and social justice, contributed to the revolutions in both the United States and France.