Book Review: Then I Am Myself the World: What Consciousness Is and How to Expand It. By Christof Koch. New York:  Basic Books, 2024,  274 pp., $30 hardcover.

A new book by Christof Koch is an event, because he's a major figure in the biological and philosophical renaissance of studies on consciousness that began in the 1990s and is in full swing today. If you watch his 2013 TEDx talk “The Scientific Pursuit of Consciousness” (TEDx Talks 2013), you'll find a humane, charismatic physicist and neuroscientist in his late 50s explaining his lifelong fascination with the subject. Koch cowrote two dozen scientific papers with the Nobel laureate Francis Crick , of DNA double helix fame, and has since published a huge number of such papers, and five books. Taking its title from a line in Wagner's (1882) Tristan and Isolde, Then I Am Myself the World is his sixth, an eclectic work written very much in the first person. Koch's main theoretical commitment remains Integrated Information Theory (IIT), a partly mathematical model according to which consciousness arises in, or is permitted by, any physical substrate whose structure has a sufficient amount of a very specific type of complexity. It was developed mainly by the psychiatric neuroscientist Giulio Tononi, with important contributions from others, especially Koch himself.

IIT is a powerful theory whose conceptual toolkit can, at least in principle, be used to assess any system's capacity for consciousness. Persuaded that it represents an important scientific advance in our understanding of how the brain's structure contributes to its powers, I remain skeptical that IIT amounts to a complete philosophical solution of the famous “Hard Problem of Consciousness” (Chalmers, 1997), which asks how mind can arise from matter. On the other hand, the less Herculean but still monumental task—the one Crick and Koch were pursuing before panpsychist

philosopher David Chalmers ever coined that phrase—was to identify the “Neural Correlates of Consciousness” (NCC). Koch finds the NCC in regions of the cortex,