The second law of thermodynamics: ds>0- Qualitative empirical phenomena. To become a science, theoretical calculations are necessary: deriving s=s (time) from ds=dq/T and experimental agreement.

s=s (time) must be consistent with all thermodynamic processes, including reversible and irreversible processes. The first law of thermodynamics satisfies this requirement. This is the requirement (universality) of the laws of natural science and physics. Otherwise, one will be expelled from the family of physical laws.