Isomorphisms
What is so “natural” about Gentzen’s “Natural Deduction”? It is that our brains are conditioned by the Environment In Which We Happen To Evolve, and the environment is governed by what we call the Law of Causality, which has been captured in the East by the Buddha’s “Dependent Origination principle” and even more precisely by Modus Ponens in the West. When this exists, that comes to be; with the arising of this, that arises....