Confined Ontic Open Systems is a new ecodynamic model based on Prigogine's thermodynamics, Ulanowicz's ontic openness and Coherence Domains with defined boundaries and constraints. The model has a wide range of applications, including ecosystems (e.g. invasive species, the lagoon of Venice), ecological economics, urban organization, the supra-molecular structure of water and global biosphere's models. The model is explained in terms of evolutionary thermodynamics and Jorgensen's ecosystems theory, namely out of chaos and eco-exergy. Particular attention is devoted to the emergence of novelties and to the role of water. COOS is an acronym for Confined Ontic Open Systems from the name of the Greek island (Kos, Coo or Coos) where the science of medicine originated at the time of Hippocrates. In Greek mythol- ogy, Asclepius, the first great doctor, ascended Mount Olympus as a god and was the first to love water. The primordial element water was considered essential in traditional Asclepiadean therapy, where the ritual of bathing was a form of purification before offering gifts to the great god of health. Hippocrates of Coos separated medicine from religion, magic and philosophy and used it in various fields. He was the first to describe the properties of water as one of the four elements (fire, earth and air) of human nature on which perfection (health, well-being) depends. Health was impaired if one or more of these elements were out of balance. Hippocrates had the merit of describing the power of water and of identifying the origin and characteristics that contribute to knowledge of diseases aris- ing from the environment, as distinct from those of human origin. He not only trusted the religion of the gods, but tried to coexist with it, teaching his students that Nature has its own life, which is not always tied to the supernatural and magic. The major problem of his studies was therefore to give medicine a theoretical instrument of effective explanation and a method of assessment that justified and upgraded the link between theory and experience. The development of the theory was seen as a new approach to medicine that was the forerunner of greater knowledge and the exchange of ideas with doctors operating outside COOS. Hippocrates therefore improved fundamental knowledge that was based on the tradition of religion, magic and observation of natural phenomena (1). The acronym COOS was coined to describe thermodynamic systems open to interactions with the outside, but that also maintain their own historical identity (ontic), because they are bound to the mem- ory of their origins. The primary aim of this paper is to present COOS as a new thermodynamic model for understanding evolutionary dynamics that create new structures and enable complexity to emerge, increasing the information in a great variety of systems, more commonly known as living systems capable of self-organization. In order to achieve this, living systems need to be protected (confined). RESULTS AND DISCUSSION 2 In order to introduce this new thermodynamic model, it is necessary to distinguish between isolated, closed and open systems. Isolated systems do not exchange energy or matter with their surround- ings. Closed systems exchange energy but not matter with the outside. Open systems exchange both energy and matter with their environment.