Who has the right to rule? Now, some of these questions have been the fodder of philosophers and religion for thousands of years. But now there was the power and the tools and the challenging notions of the Scientific Revolution. And this philosophical movement that is really tied to the Scientific Revolution is known as the Enlightenment. And just to have an example of the thinking during the Enlightenment, here is a passage from John Locke, who's considered one of the pillars of the Enlightenment. This is published in 1689. It's the second treatise concerning civil government.