[New horizons in medicine. The attractors]

The discovery of the fact that chaotic systems can suddenly coagulate into deterministic systems, and that deterministic systems can precipitate into chaotic systems has, on the one hand, clearly revealed the limits of the Cartesian geometrization of random phenomena, and on the other, has made in possible to identify the attractor as the reference entity when studying the functional dynamics of biological systems. The attractors is identified as the point of equilibrium upon which the behaviour of a dynamic system stabilizes and towards which it is constantly attracted. In some systems the attractor is identified as an "ideal" optimum reference point termed "the point". In other systems, however, the attractor is identified as a closed curve: "the ultimate cycle". Lastly, in other systems the attractor is identified as a surface in which the space of the states delimits a flat doughnut-shaped image constituting a "torus". The recent discovery of the laws governing deterministic chaos has made it possible to identify a new type of attractor termed the "strange attractor". This attractor has a fractal dimension (i.e. one midway between linear and plane), is of finite dimension and depends on the initial condition of the system. In many biological functions it is now possible to demonstrate the presence of attractors that operate starting from different initial conditions or that vary with time or that display both these conditions.(ABSTRACT TRUNCATED AT 250 WORDS)