Leonhard Euler's methods and ideas live in the thermodynamic hierarchical theory of biological evolution

It is well known that Leonhard Euler's works were of outstanding importance for the creation of modern science. In this article, the role of the brilliant Euler in the development of classical (equilibrium) thermodynamics and the quasi-equilibrium thermodynamics of quasi-closed systems is considered. Some of Euler's important methods and ideas are a significant part of the mathematical basis of not only equilibrium thermodynamics but also modern hierarchical thermodynamics. To a certain approximation, Clausius and Gibbs' thermodynamics is applied to describing the evolution of living systems. This is possible due to the law of temporal hierarchies and the premise that the functions of state of living systems have real physical meaning at practically all hierarchical levels and at every moment of time. It is shown that the principle of substance stability - the thermodynamic feedback principle - is applicable to all biological systems. It boils down for different temporal hierarchies to the following: during the formation (self-assembly) of the most thermodynamically stable structures at the highest hierarchical level (j), e.g., the supramolecular level, in accordance with the second law, Nature spontaneously uses predominantly the (available for the given local part of the biological system) least thermodynamically stable structures belonging to a lower level, for example, the molecular level (j-1). The principle can be also applied to understructure hierarchical levels of any temporal hierarchy. There are also facts that corroborate the application of the principle to social temporal and structural hierarchies. The application of the principle to problems of sociology and politics is discussed.©2007 by IJAMAS, CESER.