  Different rate theories yielded similar forms of rates constants consistent
with the phenomenological Arrhenius law, although they were derived from
various branches of physics including classical thermodynamics, statistical and
quantum mechanics. This convergence supports the validity of the Arrhenius law
but also suggests the existence of an even simpler underlying principle. A
reductionnist approach is proposed here in which the energetic exponential
factor is a conditional probability of sufficient energy and the
pre-exponential factor is the frequency of recurrence of the configuration
favorable to the reaction, itself proportional to a configurational probability
in a chaotic system. This minimalist while rigorous mathematical approach makes
it possible to bypass certain questionable postulates of more sophisticated
theories and clarifies the meaning of the different types of energies used:
activation energy, threshold energy and chemical energy.
