Describing Anderson’s approach to physics, Yu recalled him saying, “Theoretical physics is not just doing calculations. It's setting up the problem so that any fool could do the calculation.”

“It is hard to overstate the importance of the ideas of Phil Anderson to the science of SFI and complexity in general," said Santa Fe Institute President David Krakauer. "His 'More is Different' article from Science in 1972 was the most important and rigorous refutation of the foolishness of reductionism for complex systems yet published. Not only did Phil articulate why confusing parts for the whole was a problem, but in the process, he explained why different fields of inquiry – from genetics to economics – needed to exist. This was a supreme act of intellectual modesty and generosity."

Complexity, by contrast, recognizes that once lots of particles come together to produce macroscopic things—such as organisms—knowing everything about particles isn’t enough to understand reality. An early pioneer of this approach was the physicist Philip W. Anderson, who succinctly framed the nascent anti-reductionist perspective with the phrase “More is different.”