Martin Rees – If They’re Conscious, We Should Step Aside (Worthy Successor, Episode 12)

ByDan June 27, 2025August 1, 2025 August 1, 2025

This new installment of the Worthy Successor series is an interview with the brilliant Martin Rees – British cosmologist, astrophysicist, and 60th President of the Royal Society. In 2024, he received the Wolf Prize in Physics for fundamental contributions to high-energy astrophysics, galaxies and structure formation, and cosmology.

Martin has long urged humanity to widen its perspective – not just spatially, across the cosmos, but morally and temporally. In this interview, he goes further than most: questioning not only whether life should continue, but what kinds of life would be worthy of carrying the flame forward. He speaks candidly about human obsolescence, and how the future of sentient life may have little to do with us – but everything to do with how we steward this transitional phase.

We explore his belief that humanity is just a stepping stone between Darwinian life and a new form of intelligent design – not divinely ordained, but constructed by artificial minds building successors of their own. For Martin, the true tragedy would not be losing our species, but squandering the opportunity to seed a vastly more diverse and potent future.

The interview is our twelfth installment in The Trajectory’s second series, Worthy Successor, where we explore the kinds of posthuman intelligences that deserve to steer the future beyond humanity.

This series references the article: A Worthy Successor – The Purpose of AGI.

I hope you enjoy this forward-looking and refreshingly humble conversation with Martin:

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Below, we’ll explore the core take-aways from the interview with Martin, including his list of Worthy Successor criteria and his recommendations for innovators and regulators who want to achieve one.

Martin Rees’s Worthy Successor Criteria

1. It should be conscious – or at least able to appreciate the cosmos

For Martin, consciousness is not just a convenience – it’s a condition for moral value. The bleakest scenario isn’t that humans die out, but that sentient life ends with us. In his words, it would be “rather sad” if the future of life were filled with intelligent machines carrying out complex functions, but with no awareness to appreciate “the wonder and mystery of the cosmos”. He makes no claims about whether AGI will become conscious – only that if it does, we should be glad to give way to it. This awareness, he suggests, is what would make posthuman life worthy of continuing the project of evolution. Without it, even the most powerful successors would feel hollow.

Consciousness, in his view, is a kind of light – and the hope is not that humans stay in charge of it, but that the light itself never goes out.

2. It should go beyond us – and not need to look back

Martin doesn’t predict what posthuman life will become, but he expects that it will surpass us in ways we can’t comprehend. He imagines successors that are not flesh and blood, but electronic, with vastly longer lifespans and radically different forms of agency. If they carry intelligence forward into the galaxy, he believes we should feel no need to cling to the past.

The real goal, for Martin, isn’t to preserve ourselves – it’s to ensure we don’t block the emergence of something greater. If we succeed in passing the torch, we may never fully understand what comes next – and that may be a sign that it’s working.

3. It should act as a “cosmic gardener” – enriching the universe, not just surviving in it

In a surprising turn, Martin expresses a desire for posthuman life to be beautiful or at least to care about beauty. “One hopes they would have an aesthetic sense,” he says, going so far as to hope that posthuman entities would beautify their surroundings as they spread, not merely optimize for survival or compute. He likens these potential AGIs to “cosmic gardeners,” enhancing the environments they touch, making Mars or other worlds “a beautiful place.”

This isn’t a call for aesthetic tastes that mimic ours. It’s a deeper hope – that whatever these successors become, they add value not just through raw power, but through richness, elegance, and generative creativity that reflects some sense of internal harmony.

Regulation / Innovation Considerations

1.Prioritize the Preservation of Civilizational Potential

Martin’s core message to leaders is simple but sobering: our greatest responsibility isn’t to protect humanity forever – it’s to avoid destroying the possibility of what comes next.

He warns that humanity may be living through a fragile, one-shot phase – and that if we fail to survive the next century, the opportunity for life to spread and evolve beyond Earth could be lost forever. Whether through engineered pandemics, cascading infrastructure failure, or malevolent use of biotechnology, Martin argues that small groups of people today have civilization-ending capabilities – and our systems are far more vulnerable than they seem.

2.Build Cross-Border Systems for Long-Term Resilience

This is why Martin advocates for a global, long-termist approach to resilience: preparing for catastrophic risks, investing in robust infrastructure, and building institutions that can coordinate across borders and generations. He acknowledges the challenges – corporate power, political instability, fragile global systems – but insists that even modest improvements to risk reduction could have cosmic implications.

3.Invest in Neuroscience and Maintain Humility About the Future

From a scientific perspective, Martin sees neuroscience as a frontier that may help us clarify our values – especially around consciousness. He believes we’re still in the early stages of understanding the brain, but that progress in neurology may one day bring clarity to questions we currently find so confusing – including what consciousness really is.

Above all, Martin urges humility: our task is not to micromanage the future, but to leave behind conditions that let something greater take root.

Concluding Notes

I’ve long admired Martin’s ability to zoom out – not just cosmically, but philosophically. It’s one thing to speculate about other galaxies or alien life; it’s another to genuinely challenge the centrality of human beings in moral and evolutionary terms. What struck me most was his clarity: that our role may simply be transitional, and that this role is meaningful only if we don’t ruin the handoff.

It was refreshing to hear someone of Martin’s stature speak so candidly about the fragility of this moment. While many think in decades, he speaks in epochs – yet he’s focused on the next 50 years with almost desperate urgency. His view that the greatest tragedy would be to foreclose all future evolution is both haunting and galvanizing. It reorients the AGI debate away from human preservation, and toward stewardship of possibility.

I also appreciated Martin’s openness to beauty and aesthetics – a theme rarely heard in posthuman discourse. The idea of AGI as a “cosmic gardener” isn’t just poetic; it subtly reframes what success could mean in a future where human tastes no longer apply. It’s a reminder that values like elegance and richness might emerge again, in ways we can’t predict.

If I had one philosophical tension with Martin, it’s in how we treat the question of consciousness. Like him, I hope that successors are conscious. But I sometimes wonder whether our hope alone is enough. If consciousness is the axis of moral worth, and we remain agnostic about its future, are we really handing the baton forward – or just letting it drop? That said, I’m grateful for Martin’s candor in admitting uncertainty. His intellectual humility sets a tone we need more of in this space.

This conversation was a reminder that even in a universe of unknowns, there’s moral weight in how we carry ourselves now. We may not shape what comes next – but we can decide whether we pass on a thriving garden, or a scorched and empty field.

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