“We have the tendency to prioritize puzzles over mysteries, because we know they can be solved. The question ‘Where is Osama bin Laden?’ was a puzzle, and when it was solved there was great jubilation. ‘How best to combat Islamist terrorism?’—arguably a much more important question—is a mystery, but it receives far less attention among the public and in the media because it is so complex and seemingly intractable.”

Ian Leslie’s Curious is difficult to put down. Fascinating from start to finish, the nonfiction piece is fundamentally a thesis paper on curiosity and its essentiality to human development—yet it reads almost like a thriller, exploring this idea from every possible angle in a way that is both engaging and well … curious.

Leslie’s main idea is that curiosity, while sometimes more present in certain people, is a fluid trait that needs to be stoked and nurtured in order to exist. He classifies curiosity into three types: diversive, epistemic, and empathic curiosity. Diversive curiosity is the kind that most people have and involves a more superficial interest in events or objects. While this type of curiosity is useful, epistemic curiosity is arguably the more important of the two. It involves a deeper understanding of a situation or an idea. Without this type of curiosity, Leslie argues, people and their organizations cannot advance. The third type, empathic curiosity, involves an interest in the feelings of others. It, too, is essential to lifelong learning and is a subject Leslie also broaches in his work.

Curious explores the difference between puzzles and mysteries, showing the reader how mysteries are essential to life. Mysteries are what keep us occupied with sometimes unanswerable questions that continue on even after we has “solved” one aspect of the problem. Mysteries spark new ideas and provide insights that can only be found by asking, “Why?”

Leslie also discusses the importance of education and why it is essential to curiosity. Children cannot just be taught how to think, Leslie argues, their brains also need to be filled with seemingly useless facts so that they may later use this material at an advanced level.

In one particularly illuminating passage, Leslie shares an anecdote, which he draws from Paul Tough’s How Children Succeed. The story is about a young boy named James who excelled at chess despite attending a generally low-achieving public school in Brooklyn. Although James was clearly intelligent, his breadth of knowledge was limited. While his teacher tried to prepare him for an exam to gain entrance into an elite school, James was ultimately unable to perform on this test.

Writes Leslie, “James failed to gain entry to Stuyvesant, whose best chess players would have been no match for him, not because he lacked curiosity, or grit, or intelligence. He failed because, unlike middle-class kids, he hadn’t been ‘stuffed with information’ from an early age.”

Leslie ends the book with seven steps on how to maintain curiosity, including being a “thinkerer” and becoming a “foxhog,” or an expert in a few areas with a broad understanding and interest in many things.

The author does an excellent job at providing clear examples, but Leslie’s book ultimately succeeds because it is sharp, fresh, and extremely well written. I believe it is the sort of concise yet meaningful work that many of the innovators he references would ultimately approve of. Leslie’s Curious is a fun, illuminating read. My only advice: purchase a copy and start reading right away.