The universe may be hiding conscious minds stranger than we can imagine

What if consciousness isn't limited to brains like ours? Philosophers Eric Schwitzgebel and Jeremy Pober suggest that consciousness could appear in many different forms of life. This includes beings made from materials very different from those on Earth.

They argue that assuming only Earth-like biology can support conscious experience is too focused on our planet. The universe is vast, with countless alien civilizations likely existing.

Consciousness Beyond Biology

Eric Schwitzgebel, a philosophy professor at the University of California, Riverside, believes consciousness probably doesn't need flesh and blood. In a new paper, he and Jeremy Pober, a researcher at the University of Lisbon, discuss this idea. They suggest conscious beings could exist even if they are built from very different materials than Earth life.

They start by assuming consciousness is real and recognizable. Their main question is whether consciousness must rely on Earth-style biology. This discussion comes as debates about conscious artificial intelligence (AI) are growing. The authors briefly touch on AI, but they don't agree on whether current systems are conscious. Still, their argument allows for the possibility that AI could become conscious in the future.

The Idea of "Substrate Flexibility"

A key idea in their paper is "substrate flexibility." This means some properties can exist in many different materials. For example, a cup can be glass, plastic, or metal. A book can be printed or digital.

Schwitzgebel and Pober argue that consciousness is similar. They believe it's not tied to one specific physical substance. Schwitzgebel noted, "The universe may contain minds stranger than we can imagine."

Diverse Alien Life

Astronomers estimate there are about 1 trillion galaxies in the observable universe. Planets are common, and many likely have environments very different from Earth's.

The philosophers estimate that at least 1,000 advanced alien civilizations have existed. They call this a conservative estimate. Other research suggests there could be more than one civilization per galaxy over its lifetime.

Astrobiologists have also considered that alien life might be built from different materials. This could include alternative amino acids, solvents, or even entirely different chemical structures.

For instance, the novel "Project Hail Mary" describes an alien with a shell of oxidized minerals, mercury blood, and a crystal brain. This creature comes from a hot world with an ammonia-rich atmosphere.

The philosophers aren't saying such exotic life definitely exists. Instead, they argue that if life can emerge in many chemical conditions, and the universe offers countless chances for life, it's unlikely every successful evolutionary path would use the exact same biological ingredients.

Earth itself shows nature's creativity. Octopuses, bees, and dogs process information differently. Evolution on our planet has created many types of nervous systems, not just one. The authors suggest the rest of the universe could show even greater diversity.

The Copernican Principle of Consciousness

The authors' main argument is inspired by the Copernican tradition in astronomy. Over time, discoveries showed that Earth is not the center of the solar system, nor is our solar system or galaxy the center of the universe. Humanity has repeatedly learned that its place in the cosmos is less special than once thought.

Schwitzgebel and Pober suggest consciousness might follow the same pattern. If many advanced species exist with very different biological structures, assuming consciousness only belongs to organisms like us would be "terrocentrism." This means giving unjustified privilege to Earth life. They call this the "Copernican principle of consciousness."

They are not saying every advanced species must be conscious. But if consciousness exists among advanced beings, it would be strange to conclude that only organisms with biology like ours could experience it.

History shows humans are not as unique as we once believed. The same lesson may apply to consciousness. It might not be rare or limited to one type of organism. Instead, consciousness could emerge whenever evolution creates the right level of complexity.

What About Artificial Intelligence?

The paper brings up questions about AI, but the authors don't claim current AI systems are conscious. Pober argues that while consciousness can exist in different materials, not every material can support it. He sees no reason to assume today's computer hardware creates conscious experience.

Schwitzgebel is more open to the idea. He believes that once we reject the need for human biology, it's harder to dismiss silicon-based systems just because they are made of silicon.

He thinks the debate has focused on the wrong question. "It's focused too much on whether silicon can duplicate a human brain and not enough on the broader question of what kinds of systems can be conscious," he said.

The paper distinguishes between specific properties and broader categories. Asking if human consciousness can be copied in a different material is specific. Human consciousness might depend on many details of human biology. Consciousness as a general idea is broader.

They compare this to flight. Asking if another creature can fly exactly like an eagle is different from asking if flight itself can happen in other forms. Hummingbirds, bats, and insects all fly, but in different ways.

Similarly, consciousness might take many forms across the universe without necessarily being like human consciousness.

Deep Dive & References

Consciousness May Not Need Biology - University of California - Riverside, 2026