The state of water in living systems: from the liquid to the jellyfish

The status of water in living systems is reviewed both from philosophical and scientific viewpoints. Starting from antique Mediterranean civilizations (Sumerian, Egyptian, Hebrew, Greek), a world trip is proposed through Norse myths, Siberian Shamanism, Hinduism, Taoism, Buddhism, Shinto, Mayan, Aztec, Inca, Aboriginal and African philosophies in order to convince that all humans share the same qualitative idea that water was a pre-requisite for life apparition. The quantitative aspect of the problem is further analyzed at the light of the scientific contributions from two leading scientists: R.A. Gortner and E.T. Jaynes. With Gortner's work it is demonstrated using the concrete example of the Jellyfish submitted at a Faraday discussion held in London in 1930, how a paradigm shift has occurred in the thirties concerning the status of bound water in the living cell. With Jaynes' work, the disastrous consequences of the entrenchment of diffusion theory in biology are critically examined and the exact meaning of the second law of thermodynamics for biological systems is given using the concrete example of muscle contraction. In conclusion, the importance of distinguishing between an ontological and epistemological level of knowledge is stressed and suggestions for reconciling scientific and philosophical approaches are given.