The remainder of this paper will be concerned with how the absolute theory of reaction rates fits philosophical conceptions of the unity of science. From the viewpoint of reduction and unity of science, the theory has a number of unique features:
Thus, in the final analysis, the achievement of the theory was primarily conceptual: it provided valuable insights into the mechanisms that drive chemical reactions at a molecular level. Hence, the absolute theory of reaction rates is a very strong example for the unity of science it is precisely one of those examples where it is hard to imagine chemistry without physics, but at the same time it is a ‘chemical’ theory in that it focuses on molecules, molecular structures, and transformations.
Eyring’s theory is noteworthy for the amount of precision it allows in the specification of the transition state at a molecular level. As we have seen, a background postulate which has no counterpart in the Arrhenius equation is that the reaction may be viewed as a translational motion along the reaction coordinate. Whereas the transition state was foreshadowed in the work of Arrhenius in the postulate of the ‘active’ form of cane sugar, the absolute theory of reaction rates is capable of explicating exactly what the transition state . In brief, its structural features are:
where is the degeneracy of the state corresponding to energy . The complete partition function for any system is complex to calculate, since it involves all electronic, translational, vibrational and rotational motions of the system with their degeneracies and corresponding energy levels. The rate formula of the absolute theory of reaction rates is given in terms of the partition functions of the reactants and the transition state by