Max Tegmark

Max Tegmark (born 1967) is a Swedish-American physicist and cosmologist at MIT, known for work on the mathematical structure of the universe before becoming one of the most visible institutional voices for AI restraint. He co-founded the Future of Life Institute in 2014 and wrote the bestselling Life 3.0: Being Human in the Age of Artificial Intelligence (2017).

The pause letter

In March 2023, weeks after GPT-4 launched, Tegmark’s institute published “Pause Giant AI Experiments: An Open Letter,” calling on all labs to immediately pause for at least six months the training of systems more powerful than GPT-4. It drew more than 30,000 signatures, including Yoshua Bengio, Stuart Russell, Elon Musk, and Steve Wozniak, and forced the question of AI risk into mainstream politics. No lab paused. Six months later Tegmark told MIT Technology Review he was unsurprised, arguing the letter’s real goal was to legitimize the conversation — and that only governments could enforce a pause, since no lab can afford to stop unilaterally.

He has since sharpened the message. Responding in November 2024 to a US congressional commission’s proposal for a “Manhattan Project” for AGI, he called the plan an insidious threat to national security and wrote flatly that “an AGI race is a suicide race.” At Web Summit that same month he rejected the arms-race framing entirely, arguing that whoever builds AGI first simply loses control first. He continues to lobby for FDA-style safety standards for frontier AI and warns that superintelligence could make human labor — and humans — economically obsolete.

Tegmark is not a blanket AI opponent: he is an AI researcher himself, and frames his position as being against uncontrollable superintelligence rather than against useful tools. But as the organizer of the debate’s single most famous protest document, he sits firmly on the brakes side of the argument.