"Knockdown" Argument Against Naturalism

[Angrboda]

I'm just going to voice my comments in no particular order without quoting the original.

First off, nature does not imply randomness. Natural processes are stochastic, that is, they combine lawful, ordered behaviors, and random behaviors. Thus to say that rationality, and the hypotheses derived from rationality are the product of randomness is incorrect in at least three aspects.

First, the laws of nature are possessed of symmetry of action, which, as proved by Noether's theorem, means that their action will result in laws of conservation (such as conservation of momentum). The consequence of this is that the laws of nature will result in lawlike behaviors. This violates the assumption that the effects of natural law are random.

Secondly, the stochastic behavior of natural processes permits the phenomenon of self-emergent order in natural systems (magnetic polarization being a prominent example). Thus, since even random natural processes can give rise to order, to suggest that all nature and rationality are necessarily the result of randomness is false.

Third, evolution is not a random process as natural selection itself is not random, but is ordered and given direction by the relationship of the instrumental utility of the phenotype of biological beings with respect to the useful resources of the environment in terms of extracting useful work in the form of reproducing copies of itself. (In other words, how "fit" for the environment a particular variation is determines whether or not that "type" will succeed or not; the match between the type and its environment is not random.) Religious people often get confused on this point because they're distracted by the fact that evolution depends on random mutations, and they infer from this that evolution is therefore a random process. It is not, because it combines non-random and random processes, it too is stochastic, not random, and it too can result in forms of self-emergent order, possibly including rationality.

Your explanation states that because naturalism entails atheism, but atheism does not entail naturalism, that therefore naturalism is the stronger hypothesis. Hypotheses aren't ranked according to the quality of "strength," and to the best of my knowledge there is no meaningful interpretation of the concept of strength with regard to hypotheses and proposition. What there is, however, is the property of scope, being the size of the class of things described and explained by the hypothesis or theory. For example, a theory of everything (TOE) would have greater scope than either a theory of relativity or of quantum mechanics, as it would describe both the big and the small, whereas the others only describe the big or the small. As a result of the entailment, naturalism would have greater scope than atheism, which is obvious. A theory or hypothesis having greater scope does not in itself imply it has greater validity, and thus naturalism isn't more true because it has greater scope.

As noted, evolution can give rise to order, and thus rationality isn't necessarily random, nor is its likelihood of arriving at the truth therefore necessarily random. What it is, is imperfect. Rationality cannot guarantee that its conclusions are correct, but it can increase the probability of its conclusions being correct by applying principles and processes which it has discovered and verified to be orderly and have lawlike behavior, to develop ordered and lawful predictions of probable character.

Your brother's argument is a variant of the argument from rationality, and there is a considerable body of literature on this apologetic argument. You might want to research the pre-existing responses to that argument before re-engaging your brother on his points and his version of it.