In the words of Alvin Plantinga, Naturalism is basically atheism-plus: there is no God and nothing like God. All that exists is matter and energy. However, since matter and energy are dynamic, then what place is left for any laws of logic, mathematics, science or morality? In order for something to be truly law-like, it cannot be dynamic.
This means that on Naturalism, there can be no objective standards of reason. In order to assert that Naturalism is true, the Naturalist must presuppose the objectivity of these laws, and so his position is self-defeating. If the Naturalist denies the objectivity of any law, then neither can Naturalism be consistently held as true.
Formally, through reductio ad absurdum:
Prove A: Supernaturalism is true.
Assume ~A: Naturalism is true.
~A --> B: If Naturalism is true, then there are no objective laws of reason.
~B: There are objective laws of reason.
Hence, ~~A: by modus tollens.
Therefore, A: by negation.