The law of temporal hierarchies makes it possible to identify quasi-closed monohierarchical systems in open polyhierarchical biological systems. It is possible to use the approaches of hierarchical quasi-equilibrium thermodynamics to establish the direction of ontogenesis and evolutionary processes. The law of temporal hierarchies helps to substantiate the idea that an overwhelming majority of supramolecular and other processes (at least structure-forming ones) in biological world take place in quasi-closed systems under regimen close to the state of equilibrium. Hence the conclusion that the relevant in vivo and in vitro processes can with equal justice be studied in terms of chemical, supramolecular, and generally speaking, hierarchical thermodynamics. The thermodynamic theory of origin, evolution and development of living systems and the thermodynamic theory of biological matter circulation boost the ideas of G. Galileo, J.K Maxwell, Ch. Darwin and other classics, based on belief that there exist universal natural laws operating at all hierarchical levels of matter. The author considers that the statements of article are connected with the cogency of equilibrium (quasi-equilibrium) thermodynamics, which is based on the method of full differentials.