A World Appears: A Journey into Consciousness (2026) is the 10th book from New York Times bestselling American author Michael Pollan, best known for his nonfiction book about human relationships to food, The Omnivore’s Dilemma (2006). His eighth book, How to Change Your Mind (2018) became a No. 1 New York Times bestseller and inspired the Netflix docuseries of the same name.

A World Appears, initially inspired by Pollan’s research on psychedelics, takes an introspective, scientific approach to the concept of consciousness. Pollan draws from interdisciplinary research across the fields of neuroscience, biology, psychology, philosophy, spiritualism, and literature to explore what consciousness is, who (or what) has it, and how it came to be. On the way, he explains complex scientific theories, philosophical debates, and universal mysteries in clear, personable, occasionally wry prose. A World Appears challenges deeply held beliefs about the nature and uniqueness of human consciousness and considers the themes of The Limits of Western Rationality, The Impact of Biases on Science, and Sentience as a Challenge to Human Uniqueness.

This guide refers to the 2026 hardcover edition from Penguin Press.

Content Warning: This guide and source material contains depictions or mentions of drug use and animal cruelty.

Summary

A World Appears is organized into four chapters plus an introduction and a coda. The introduction provides context for the topic of consciousness research. The four chapters, organized by subheadings, each explore a particular level or element of consciousness: sentience, feeling, thought, and self. Finally, the coda describes a personal experience Pollan has at the end of the research, which alters his final conclusions.

In the Introduction, Pollan describes a bet placed by two consciousness researchers, Christof Koch and David Chalmers. Christof Koch and his mentor were neuroscientists at the leading edge of consciousness research in the 1980s and 90s. They believed that they would soon identify the physical origins of consciousness in the brain. David Chalmers, a philosopher who had made a splashy debut in consciousness research in 1994, disagreed. Chalmers doubted that neuroscience could answer the hard problem of consciousness: the question of why mental operations should give rise to any feeling or sensation of subjective experience at all. Koch and Chalmers made a wager that science would locate the origins of consciousness in the brain within 25 years. Koch lost the bet in 2023.

Chapter 1 explores the concept of sentience, an elemental form or precursor to full consciousness. To discuss the ubiquity of sentience in the natural world, Pollan looks to plants.

Recently, scientists have begun to argue that plants have sentience. Research conducted by plant neurobiologist Stefano Mancuso has shown that plants can communicate with each other, perceive and respond to their environments, and even sleep, demonstrating awareness, intelligence, and sentience.

To better understand how sentience might arise in a living organism, Pollan speaks with neuroscientist Karl Friston, who argues that the foundation of sentience and consciousness is homeostasis—the drive of all living things to resist entropy, reduce surprise, and maintain their internal systems for survival. Pollan notes that while this argument explains how perceptions outside and inside the body impact the brain, it does not yet answer the hard problem of why.

Chapter 2 explores the concept of feelings. According to neurologist Antonio Damasio, feelings are the origins of consciousness, providing a “bridge” between the body and the mind. Damasio, like Friston, argues that homeostasis is the foundation for this. Basic feelings are the body’s way of telling the mind that the baseline for survival has changed, urging the mind to react and re-establish balance.

While Damasio believes this to be a biological phenomenon only, Friston and his protégé, Mark Solms, believe that homeostasis and consciousness are grounded in physics and information theory, and therefore any sufficiently complex system could conceivably be conscious.

This leads to a discussion of artificial intelligence and the potential of creating conscious machines. While no scientist has yet succeeded, the consensus is that it is hypothetically possible. However, Pollan notes that this argument starts from the unquestioned assumption that brains function like computers, despite evidence to the contrary, and does not account for the biological, embodied origins of feelings.

Chapter 3 explores thought. Few researchers discuss thought in their theories of consciousness because thought is so difficult to define or identify, whereas concrete mental operations like visual or auditory perception have proven easier to locate in the brain. Due to the limitations of neurologists and hard science on this topic, Pollan now turns to the work of phenomenologists, who study consciousness from within.

William James, an early pioneer of phenomenology, approached the study of thought with meticulous description and coined the term “stream of consciousness” (128), which describes thoughts as continuously flowing like water. Pollan next turns to psychologist Russell Hurlburt, who attempts to isolate and describe individual thoughts as they arise, and psychologist Kalina Christoff Hadjiilieva who studies spontaneous, or unconscious, thought.

In the fourth chapter, Pollan explores the concept of self, one of the more difficult elements of consciousness to define. He first explains early theories, such as Descartes’s belief that the self is the only fully knowable and certain aspect of reality. In contrast, 18th-century philosopher David Hume argued that it is impossible to locate the self within one’s perceptions, and this calls into question the existence of a real, individual self at all.

According to current researchers, the self is made of experiences and memories that give people a sense of continuity. Some scientists argue that this sense of self is an illusion that is not necessary for consciousness to exist. Moreover, the insights of psychedelics research and spiritual practices like Buddhism suggest that one’s ability to shed that sense of self allows for greater understanding and joy.

Finally, in the coda, Pollan describes his experience at a Buddhist Zen center, where he spent several days living in a cave. He meditates on what he has learned and attempts to strip away his sense of self. During one successful attempt, he feels fully connected with the universe and concludes that consciousness is not a puzzle to be solved but a way of living to be practiced.