Ⅱ. Disadvantages of Existent Definitions of Life

The definition of life is related with the origin of life, both of which rely on the the understanding of life. At present, there are two kinds of definitions of life, one is the Definition by Function, which defines life by its properties and functions, and the other is the Structural Definition (or the Entity Definition), which defines life by special structure of life. There are two kinds of the Definition by Function, one is the Cluster Definition which regards life as an assemblage of many properties, and the other is the Root Property Definition, which consider one or a few properties as the essential property of life (Li, 2002, p.24-39). All of these definitions have obvious disadvantages.

Disadvantages of Four Root Property Definitions

Four Root Property Definitions are the Theories of Life as Metabolism, Supple Adaptation, Information and the Here- dity.

The Theory of Life as Metabolism. The Theory of Life as Metabolism considers the continuous process of meta- bolism of material and energy as the basic property of life. Erwin Schrödinger developed the Theory of Life as Metabolism and created the theory of negative entropy in his book What Is Life, “Thus a living organism continually increases its entropy.” “It can only keep aloof from it, i.e. alive, by continually drawing from its environment negative entropy” (Schrödinger, 1992). This opinion is continued by the Theory of Dissipative Structure.

These theories are not right. Although every kind of life is a self-organizational system and a dissipative structure, not all self-organizational systems and dissipative structures are lives. Some non-living things, like laser and internal combustion engine, are capable of self-organization, drawing negative entropy and dissi- pating it, too. So self-organization, drawing negative entropy and dissipation are not sufficient conditions of life.

The essential property of life must be possessed by all creatures, and must not be possessed by any non-living things. If the requirement is relaxed, we can list many properties of life to fit. For example, each life must be matter, and what is not matter is not life obviously.