nonlife

Nonlife refers to the condition of not being alive. It encompasses matter, systems, and objects that do not display the organized biological processes commonly associated with living beings. In biology, life is often defined by a combination of properties such as metabolism, growth, reproduction, response to stimuli, homeostasis, and the capacity to evolve. Nonliving things either never possessed these properties or have ceased to display them.

The term is used to contrast living systems with everything else. Examples of nonliving matter include minerals, rocks, water, air, and most manufactured objects such as tools and electronics, as well as celestial bodies and geological formations. Some entities that challenge simple classification—such as viruses—are debated: outside a host or without metabolism, many definitions treat them as nonliving, though some view them as borderline or parasite-like life forms in certain contexts.

The boundary between life and nonlife is a topic of philosophical and scientific discussion. Some perspectives treat life as a process rather than a substance, which can blur distinctions with nonlife. In origins-of-life research and astrobiology, scientists study how nonliving chemistry could lead to living systems, a transition known as abiogenesis.

In everyday language, nonlife is a useful contrast to living beings and to dead organisms. The term serves to categorize the vast majority of the material world that does not fulfill the criteria typically used to define life.