Redefining the Human: Tobias Rees on AI, Microbiomes, and the New Brain

In this episode of We Are ETH, Susan Kish speaks with Tobias Rees, philosopher, and anthropologist, about how science and technology are rewriting our idea of “human”. Tobias explains the shift from seeing the brain as fixed chemistry to a living system that renews and adapts. He explores how the microbiome and climate research dissolve the old boundary between humans and nature. Then he turns to AI as an “in-between” presence: a built system that learns, models, and creates in ways once reserved for living beings. The result is a fresh take on agency, identity, and participation in a world where machines and organisms increasingly overlap. Along the way Rees shares the moments that shaped his thinking, the projects he is pursuing now and the practices that keep his ideas moving. Bold, clear and provocative, this is a fast track into the future of what we are.

Chapters:

(01:42) The brain: From fixed organ to living system

(06:04) The human as a concept

(07:43) Ancient philosophy: Who counted as human?

(09:54) The birth of universal humanity

(12:09) Microbiomes and climate change: Rethinking nature

(13:08) AI: Between machine and being

(16:03) Tobias's work and philosophy

(17:04) Growing up without career expectations

(18:03) Reading recommendations and daily practices

books and podcasts mentioned in this episode:

• The Genius Of Trees by Harriet Rix
• Possible by Reid Hoffman and Aria Finger
• No Priors by Sarah Guo and Elad Gil
• ZEIT Literatur Podcast "Was liest du gerade?"
• F.A.Z. Literatur Podcast