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Limits of knowledge

By January 17, 2023No Comments

From a special in New Scientist

This is a version of a thought experiment favoured by philosophers, first described with reference to grains of sand in a heap, called the sorites paradox (from the Greek word for “heap”). It is often used as evidence that classical logic might be insufficient to describe the world around us.

But some philosophers argue that logic itself needs a refresh. One approach is to say that there are different degrees of truth. Take the case of my hair removal. Halfway through the process of plucking, I am still not bald, but I am less “not bald” than I was at the start. Fuzzy logic, a kind of computing using degrees of truth rather than 1s and 0s, was introduced by computer scientist Lotfi Zadeh in 1965. It is still used in some artificial intelligence systems today, like IBM’s Watson.

It is a question that David Wolpert at the Santa Fe Institute in New Mexico has been thinking about for decades. In a recent monograph, he spelled out his argument that it is more likely than not that there is some higher mode of logic that could be used to understand the universe, but that human minds wouldn’t be able to grasp.

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