Defining life: no current solution (Introduction)

by David Turell , Tuesday, March 09, 2021, 21:07 (1355 days ago) @ David Turell

The author wonders why:

https://www.quantamagazine.org/what-is-life-its-vast-diversity-defies-easy-definition-2...

"With scientists adrift in an ocean of definitions, philosophers rowed out to offer lifelines.

"Some tried to soothe the debate, assuring the scientists they could learn to live with the abundance. We have no need to zero in on the One True Definition of Life, they argued, because working definitions are good enough. NASA can come up with whatever definition helps them build the best machine for searching for life on other planets and moons. Physicians can use a different one to map the blurry boundary that sets life apart from death.

***

"In 2011, Trifonov reviewed 123 definitions of life. Each was different, but the same words showed up again and again in many of them. Trifonov analyzed the linguistic structure of the definitions and sorted them into categories. Beneath their variations, Trifonov found an underlying core. He concluded that all the definitions agreed on one thing: life is self‐reproduction with variations.

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"Some philosophers have suggested that we need to think more carefully about how we give a word like life its meaning. Instead of building definitions first, we should start by thinking about the things we’re trying to define. We can let them speak for themselves.

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"The Lund researchers found that they could sort things pretty well into the living and the nonliving without getting tied up in an argument over the perfect definition of life. They propose that we can call something alive if it has a number of properties that are associated with being alive. It doesn’t have to have all those properties, nor does it even need exactly the same set found in any other living thing. Family resemblances are enough.

***

"As a philosopher, Cleland recognized that the scientists were making a mistake. Their error didn’t have to do with determinate attributes or some other fine philosophical point understood only by a few logicians. It was a fundamental blunder that got in the way of the science itself. Cleland laid out the nature of this mistake in a paper, and in 2001 she traveled to Washington, D.C., to deliver it at a meeting of the American Association for the Advancement of Science. She stood up before an audience made up mostly of scientists, and told them it was pointless to try to find a definition of life.

"Fortunately, some people who heard Cleland talk thought she was onto something. She began collaborating with astrobiologists to explore the implications of her ideas. Over the course of two decades she published a series of papers, culminating in a book, The Quest for a Universal Theory of Life.

"The trouble that scientists had with defining life had nothing to do with the particulars of life’s hallmarks such as homeostasis or evolution. It had to do with the nature of definitions themselves — something that scientists rarely stopped to consider. “Definitions,” Cleland wrote, “are not the proper tools for answering the scientific question ‘what is life?’

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"Life is different. It is not the sort of thing that can be defined simply by linking together concepts. As a result, it’s futile to search for a laundry list of features that will turn out to be the real definition of life. “We don’t want to know what the word life means to us,” Cleland said. “We want to know what life is.” And if we want to satisfy our desire, Cleland argues, we need to give up our search for a definition."

Comment: The bold is the real point. We recognize what is living, and we can study it. It is like The famous quote from Supreme court Justice Powell: "I know pornography when I see it, but I cannot define it."