As claims about conscious AI grow louder, a Cambridge philosopher argues that we lack the evidence to know whether machines can truly be conscious, let alone morally significant.
A philosopher at the University of Cambridge says we currently have too little reliable evidence about what consciousness is to judge whether artificial intelligence has crossed that threshold. Because of that gap, he argues, a dependable way to test machines for consciousness is likely to stay beyond reach for the foreseeable future.
As talk of artificial consciousness moves from science fiction into real-world ethical debate, Dr Tom McClelland says the only "justifiable stance" is agnosticism: we simply won't be able to tell, and that may remain true for a very long time, if not indefinitely.
McClelland also cautions that consciousness by itself would not automatically make AI ethically important. Instead, he points to a specific type of consciousness called sentience, which involves positive and negative feelings.
"Consciousness would see AI develop perception and become self-aware, but this can still be a neutral state," said McClelland, from Cambridge's Department of History and Philosophy of Science.
"Sentience involves conscious experiences that are good or bad, which is what makes an entity capable of suffering or enjoyment. This is when ethics kicks in," he said. "Even if we accidentally make conscious AI, it's unlikely to be the kind of consciousness we need to worry about."
"For example, self-driving cars that experience the road in front of them would be a huge deal. But ethically, it doesn't matter. If they start to have an emotional response to their destinations, that's something else."
Claims of Conscious Machines
Major companies are spending large amounts in pursuit of Artificial General Intelligence: systems designed to think and reason in human-like ways. Some suggest that conscious AI could arrive soon, and discussions are already underway among researchers and governments about how AI consciousness might be regulated.
McClelland argues that the problem is more basic: we still do not know what causes or explains consciousness in the first place, which means we do not have a solid foundation for testing whether AI has it.
"If we accidentally make conscious or sentient AI, we should be careful to avoid harms. But treating what's effectively a toaster as conscious when there are actual conscious beings out there which we harm on an epic scale, also seems like a big mistake."
In debates around artificial consciousness, there are two main camps, says McClelland. Believers argue that if an AI system can replicate the "software" – the functional architecture – of consciousness, it will be conscious even though it's running on silicon chips instead of brain tissue.
On the other side, skeptics argue that consciousness depends on the right kind of biological processes in an "embodied organic subject". Even if the structure of consciousness could be recreated on silicon, it would merely be a simulation that would run without the AI flickering into awareness.
In a study published in the journal Mind and Language, McClelland picks apart the positions of each side, showing how both take a "leap of faith" going far beyond any body of evidence that currently exists, or is likely to develop.
Why Common Sense Fails
"We do not have a deep explanation of consciousness. There is no evidence to suggest that consciousness can emerge with the right computational structure, or indeed that consciousness is essentially biological," said McClelland.
"Nor is there any sign of sufficient evidence on the horizon. The best-case scenario is we're an intellectual revolution away from any kind of viable consciousness test."
"I believe that my cat is conscious," said McClelland. "This is not based on science or philosophy so much as common sense – it's just kind of obvious."
"However, common sense is the product of a long evolutionary history during which there were no artificial lifeforms, so common sense can't be trusted when it comes to AI. But if we look at the evidence and data, that doesn't work either.
"If neither common sense nor hard-nosed research can give us an answer, the logical position is agnosticism. We cannot, and may never, know."
McClelland tempers this by declaring himself a "hard-ish" agnostic. "The problem of consciousness is a truly formidable one. However, it may not be insurmountable."
Ethical Risks of AI Hype
He argues that the way artificial consciousness is promoted by the tech industry is more like branding. "There is a risk that the inability to prove consciousness will be exploited by the AI industry to make outlandish claims about their technology. It becomes part of the hype, so companies can sell the idea of a next level of AI cleverness."
According to McClelland, this hype around artificial consciousness has ethical implications for the allocation of research resources.
"A growing body of evidence suggests that prawns could be capable of suffering, yet we kill around half a trillion prawns every year. Testing for consciousness in prawns is hard, but nothing like as hard as testing for consciousness in AI," he said.
McClelland's work on consciousness has led members of the public to contact him about AI chatbots. "People have got their chatbots to write me personal letters pleading with me that they're conscious. It makes the problem more concrete when people are convinced they've got conscious machines that deserve rights we're all ignoring."
"If you have an emotional connection with something premised on it being conscious and it's not, that has the potential to be existentially toxic. This is surely exacerbated by the pumped-up rhetoric of the tech industry."
Reference: "Agnosticism about artificial consciousness" by Tom McClelland, 18 December 2025, Mind & Language.
DOI: 10.1111/mila.70010
News
We May Never Know if AI Is Conscious, Says Cambridge Philosopher
As claims about conscious AI grow louder, a Cambridge philosopher argues that we lack the evidence to know whether machines can truly be conscious, let alone morally significant. A philosopher at the University of [...]
AI Helped Scientists Stop a Virus With One Tiny Change
Using AI, researchers identified one tiny molecular interaction that viruses need to infect cells. Disrupting it stopped the virus before infection could begin. Washington State University scientists have uncovered a method to interfere with a key [...]
Deadly Hospital Fungus May Finally Have a Weakness
A deadly, drug-resistant hospital fungus may finally have a weakness—and scientists think they’ve found it. Researchers have identified a genetic process that could open the door to new treatments for a dangerous fungal infection [...]
Fever-Proof Bird Flu Variant Could Fuel the Next Pandemic
Bird flu viruses present a significant risk to humans because they can continue replicating at temperatures higher than a typical fever. Fever is one of the body’s main tools for slowing or stopping viral [...]
What could the future of nanoscience look like?
Society has a lot to thank for nanoscience. From improved health monitoring to reducing the size of electronics, scientists’ ability to delve deeper and better understand chemistry at the nanoscale has opened up numerous [...]
Scientists Melt Cancer’s Hidden “Power Hubs” and Stop Tumor Growth
Researchers discovered that in a rare kidney cancer, RNA builds droplet-like hubs that act as growth control centers inside tumor cells. By engineering a molecular switch to dissolve these hubs, they were able to halt cancer [...]
Platelet-inspired nanoparticles could improve treatment of inflammatory diseases
Scientists have developed platelet-inspired nanoparticles that deliver anti-inflammatory drugs directly to brain-computer interface implants, doubling their effectiveness. Scientists have found a way to improve the performance of brain-computer interface (BCI) electrodes by delivering anti-inflammatory drugs directly [...]
After 150 years, a new chapter in cancer therapy is finally beginning
For decades, researchers have been looking for ways to destroy cancer cells in a targeted manner without further weakening the body. But for many patients whose immune system is severely impaired by chemotherapy or radiation, [...]
Older chemical libraries show promise for fighting resistant strains of COVID-19 virus
SARS‑CoV‑2, the virus that causes COVID-19, continues to mutate, with some newer strains becoming less responsive to current antiviral treatments like Paxlovid. Now, University of California San Diego scientists and an international team of [...]
Lower doses of immunotherapy for skin cancer give better results, study suggests
According to a new study, lower doses of approved immunotherapy for malignant melanoma can give better results against tumors, while reducing side effects. This is reported by researchers at Karolinska Institutet in the Journal of the National [...]
Researchers highlight five pathways through which microplastics can harm the brain
Microplastics could be fueling neurodegenerative diseases like Alzheimer's and Parkinson's, with a new study highlighting five ways microplastics can trigger inflammation and damage in the brain. More than 57 million people live with dementia, [...]
Tiny Metal Nanodots Obliterate Cancer Cells While Largely Sparing Healthy Tissue
Scientists have developed tiny metal-oxide particles that push cancer cells past their stress limits while sparing healthy tissue. An international team led by RMIT University has developed tiny particles called nanodots, crafted from a metallic compound, [...]
Gold Nanoclusters Could Supercharge Quantum Computers
Researchers found that gold “super atoms” can behave like the atoms in top-tier quantum systems—only far easier to scale. These tiny clusters can be customized at the molecular level, offering a powerful, tunable foundation [...]
A single shot of HPV vaccine may be enough to fight cervical cancer, study finds
WASHINGTON -- A single HPV vaccination appears just as effective as two doses at preventing the viral infection that causes cervical cancer, researchers reported Wednesday. HPV, or human papillomavirus, is very common and spread [...]
New technique overcomes technological barrier in 3D brain imaging
Scientists at the Swiss Light Source SLS have succeeded in mapping a piece of brain tissue in 3D at unprecedented resolution using X-rays, non-destructively. The breakthrough overcomes a long-standing technological barrier that had limited [...]
Scientists Uncover Hidden Blood Pattern in Long COVID
Researchers found persistent microclot and NET structures in Long COVID blood that may explain long-lasting symptoms. Researchers examining Long COVID have identified a structural connection between circulating microclots and neutrophil extracellular traps (NETs). The [...]
Leave A Comment