How did Linus Pauling and Emil Zuckerkandl describe life as a relationship among molecules?

In the context of systems biology, American theoretical physical chemist Linus Pauling and French biologist Emil Zuckerkandl insightfully captured the nature of biological systems by stating, "Life is a relationship among molecules and not a property of any one molecule."1

This perspective emphasizes that life is defined by the interactions, relationships, and collective properties of many molecular systems rather than the characteristics of individual components. It highlights that biological function relies on the information contained within molecular structures—specifically the chemical properties that enable molecules to recognize and bind to one another. By viewing life as a relationship, scientists can better understand how emergent properties arise from the collective behavior of molecular parts, a concept that is central to modern systems biology.1