What Does It Mean to Think? Sebastiaan Mathôt Explores the Thought Worlds of Humans, Animals, Plants, and AI

Recently, A World Full of Thinkers was published, the first popular science book by cognitive psychologist Sebastiaan Mathôt. In the book, he takes readers on a journey through the surprising forms of thinking in humans, animals, plants, and artificial intelligence—and poses the ultimate question: what is consciousness?

Mathôt, affiliated with the Faculty of Behavioural and Social Sciences, specializes in eye movements, attention, and visual perception. His research focuses particularly on the pupil: why does it constrict in bright light or when we look at something up close, and why does it dilate with effort or emotion? Even small changes in pupil size affect how sharply and vividly we perceive the world.

Not Unique

In A World Full of Thinkers, Mathôt looks beyond humans alone. What does it mean to think or to feel? How does a carnivorous plant experience its environment, what goes on in an octopus, or in a chatbot? “For a long time, we considered ourselves unique in our ability to think,” says Mathôt. “But if you understand thinking as a combination of building blocks like perception, memory, emotion, and sensation, then you can even speak of a form of thinking in flowers that turn with the sun. Not like Rodin’s pensive figure, but as the ability to perceive.”

A Journey of Discovery


The book does not aim to present a grand theory of thinking or solve societal problems. Instead, Mathôt invites readers on a journey of discovery, in the spirit of Alexander von Humboldt: “You describe what you see.” He presents his work as a “catalog of ways of thinking”—a walk through diverse forms of thought, guided by curiosity. “I find this subject fascinating myself, and I hope readers will experience the same sense of wonder.”

Variation


This journey passes by bumblebees sheltering together from the rain, climbing plants that imitate their neighbors, and jumping spiders planning routes to stalk prey. Sophisticated yet simple processes, these examples show that thinking takes far more forms than we usually assume.

Consciousness


The final chapter addresses perhaps the most fascinating question: consciousness. Does AI possess it, or could it emerge in the future? According to Mathôt, there is no definitive answer; we simply cannot know whether AI can have consciousness. During writing, he became convinced that emotion and the drive for self-preservation play a key role. “A bumblebee that stings, or a cell that tries to sustain itself: those are forms of survival. AI lacks that core drive to achieve something in order to continue existing. A self-driving car or a robot lawnmower comes closer, because it also has a ‘body’ that wants to preserve itself.”

Mathôt leaves readers with a thought that lingers: perhaps thinking and feeling are not as uniquely human as we once believed—and perhaps the thinkers around us are more numerous and surprising than we ever imagined.

A World Full of Thinkers A World Full of Thinkers is now available in stores. On September 22, Mathôt will speak about his book at Studium Generale.

• Profile Sebastiaan Mathot

• Lecture Studium Generale 22 September