1189 David Hume

Of the 18 key figures that created The Enlightenment, the ideology that underpins Western society, David Hume, who explained that passion rather than reason governs human behavior, is the most insightful. Obviously, wise thinkers throughout history had recognized this most basic fact of psychology but it was Hume’s placement in Scotland during the 18th century that made him stand out. Modern science has supported his hypothesis with the discovery of chemicals in the brain that are the source of motivation: dopamine, serotonin, adrenaline, etc. This was a highly controversial position at the time; even now because it’s counter to altruistic or theological explanations, and puts homo sapiens on the same level with all living creatures. Hume’s ideas also put him at odds with other prominent figures like Voltaire & Rousseau, who thought that knowledge could be derived by reason alone without experiment or experience. However, Hume did find common cause with John Locke, another towering Enlightenment contributor, and others. What makes this ironic is that Hume made his scientific observations without the tools of science because it was The Enlightenment that developed science.