A definition of the term “life”, if understood as one element in a supposed class of extraterrestrial and prebiological phenomena, is shown to be logically impossible because life is the sole known element of that class. Instead, the properties of the class of “bioids”, defined as the class of “open systems which can exist in several steady states” (DECKER and SPEIDEL, Chemiedozententagung, Hamburg 1968; DECKER, 6th FEBS Meeting, Madrid 1969, Abstracts Vol. p. 146) are explored. It contains all lifelike systems as a subclass and is equivalent to the class of thermodynamical open systems which, simultaneously, are “systems” as defined in kybernetics: consisting of “elements” (steady states) and “relations” (transitions between such). Generalizations of the concepts of “species” (as steady states), “mutation” (as transition between steady states) and “evolution by mutation and selection of the fittest” are defined in this class, making those concepts independent of nucleic acids, proteins, macromolecules and linear matrices which may be special features of terrestrial life or advanced systems only. This is derived on the example of the kinetics of a chemical bioid, where two autocatalysts compete for one substrate. The autocatalytic condensation of formaldehyde into monosaccharides was investigated in a flow reactor as an example of a chemical bioid. The transition of the nonreacting into a reacting state was seen in the kinetics; further transitions in the very complex reaction seemed to follow without lag time the changes in the reaction conditions; the elucidation of supposed additional states requires further differentiation of the complex reaction products. The consumption of formaldehyde could be followed down to very high dilutions, to 20°C and to a formaldehyde supply of 1 g per day per litre. The results allow, by extrapolation, the conclusion that a formaldehyde bioid presumably could subsist in a reacting state under prebiological conditions in 10 cm deep water on a photochemical formaldehyde supply of 10-100 mg per day per qm from a methane atmosphere. Such a system would act as an information source providing a steady supply of complex carbon compounds from a C 1 precursor.