"Violence, in many ways, has plunged over the course of history,” science speaker Steven Pinker tells Bill Gates in a recent interview. “Half a century without a great power war is unprecedented.”

In a series of interviews with the former chief executive of Microsoft, Pinker discusses findings he presented in his groundbreaking book, The Better Angels of Our Nature: Why Violence Has Declined—which Gates described as “one of the most important books [he's] ever read.” Named among Newsweek's “100 Americans for the Next Century,” the leading cognitive scientist uses wit and pop culture references as tools to articulately share his profound discoveries with experts and non-specialists alike. After receiving statistics from several leading scholars, along with his own research, Pinker found revelatory evidence to support the theory that society is becoming less violent.

“It is a profound message that we have been doing something right,” Pinker said of his findings. “Unless you actually look at the numbers, over time, you don't realize that even if things are bad—they used to be worse. What we can do does make a difference.”