Knowledge comes into the world by many paths. The Knowledge Machine (subtitled How Irrationality Created Modern Science) has a lot to say about the process by which scientists since the 17^th century have created scientific knowledge.

The book begins with a question: “Why did it take so long—two thousand years after the invention of philosophy and mathematics—for the human race to start using science to learn the secrets of the universe?”

The question is brilliant and not one that had been asked before. Asking the right question can open up new vistas, like drawing back a curtain on stage. I am reminded of the question that was asked of Jared Diamond, which seeded his book Guns, Germs, and Steel: “Why is it that you white people developed so much cargo and brought it to New Guinea, but we black people had little cargo of our own?” That is, why did some cultures or civilizations come to dominate others?

Once you ask the right question, then you have to have the perception to track down the answers, even if the answers seem at odds with your worldview or contradict established ideas about the world.

Michael Strevens looks first at how scientists carry out scientific investigations, at how scientists think about doing science, instead of rehashing the history of the Enlightenment and the Scientific Revolution. Once he grasps the rules by which scientists operate, then he looks for explanations as to why, prior to the 17^th century, this modern scientific way of looking at the world did not exist.

Along the way, the author confronts ideas with which he’s not comfortable. He’s a philosopher. Perhaps that explains why he uses the term “irrational” to describe the scientific thought process, which firmly excludes certain kinds of philosophical modes of thought. Nevertheless, he concedes that science, for all its irrationality, has achieved much that has improved the lot of humans and will be needed to confront future challenges.

I cannot adequately summarize his arguments; it’s best left for each reader to discover them on her own. He writes clearly and concisely and, occasionally, explains difficult concepts with clever analogies, which illustrate his deep grasp of the subject. Altogether an enjoyable and illuminating read.