Imagine you could take a cosmic mixing bowl and cook up reality from scratch. It would be a strange kind of baking, with the end results including everything from space-time and satellites to cats and the cosmic web. But here’s the question: what would be the basic ingredient you’d need to use? I first got introduced to this kind of question in seventh grade, sitting in a class I had never taken before: physics. Although this introductory class was mostly about balls rolling down hills, I was taught that the methods of physics ought to have limitless reach – an idea called reductionism. Physics should be able to identify the essential ingredients of reality and show how to combine them from scratch into anything and everything. Immediately, I decided to become a physicist. But now, many years and several degrees later, I am less sure that physics holds all the answers. Take something like my sense of self: is that really a consequence of some equation that we haven’t yet derived? If I think about questions like these hard enough, I am left feeling rattled, wondering whether I have become a bad physicist. So, I decided to engage with these doubts and work out what I really think about the essence of reality. I was inspired by two recent books that come at these questions from opposite ends of the spectrum. One argues that all reality is built from nothing more than quantum fields. “Everything else is just in our minds. All our concepts are illusions,” says its author, Liam Graham. The other insists that the most essential ingredient of reality is conscious experience. “That’s what is fundamentally real,” says Adam Frank at the University of Rochester in New York state, one of the book’s co-authors. Deciding whether either of