If physicalism (e.g. Scientific Realism) is true, then our beliefs and experiences are a result of the universe’s initial conditions and causal laws (which may have a probabilistic aspect). Therefore, assuming physicalism, we don’t present or believe arguments for reasons of logic or rationality. Instead, the arguments that we present and believe are those entailed by the physics that underlies our experiences. It is *possible* that we live in a universe whose initial conditions and causal laws are such that our arguments *are* logical. But in a physicalist framework that’s not why we present or believe those arguments. The fact that the arguments may be logical is superfluous to why we make or believe them. Obviously there’s nothing that says that our physically generated experiences and beliefs have to be true or logical. In fact, we have dreams, hallucinations, delusions, schizophrenics, and madmen as proof that there is no such requirement. So arguing for physicalism is making an argument that states that no one presents or believes arguments for reasons of logic. Note that this exact same argument can be used against any position which posits that consciousness is caused by or results from some underlying process.