David Christian explores the concept of thinking in the context of the universe’s history. He argues that thinking is an emergent property of increasingly complex networks, from stars to living organisms. Living organisms, unlike inanimate objects, must adapt to unstable environments, leading to homeostasis and decision-making abilities. Neurons in brains expand these abilities exponentially. Humans have added another layer through “collective learning,” enabled by language and technology, which has become global in the last two centuries. The combination of human brains and computers has created an immensely powerful thinking machine. Christian questions whether this machine has any coherent direction or control, expressing concern that its disparate parts could lead to its breakdown, with catastrophic implications for future generations.