[What are the existential bases of living systems? A new paradigm].

Biology is searching for a paradigm of life and is proceeding from an inductive, empirical to a deductive, formal science. All life phenomena result from the efficacy of a principle, i.e., systemic information, which is not reducible to physics and chemistry. Systemic information, together with genetic information engraved on macromolecules and matter described by physics and chemistry, represents the existential basis of life. A strategy is developed which makes it possible to determine the systemic information of a living organism provided there is enough knowledge of the organism concerned.