Rosenberg's Argument Against Beliefs

[Neo-Scholastic]

I'm perfectly willing to accept that beliefs as the author defines them do not exist. That's not saying the same thing as that beliefs qua beliefs do not exist.

A common understanding of the term ‘belief’ includes intentionality. If you have an alternate definition that excludes intentionality, I would enjoy learning it. Doing so entails a risk. You run the risk of performing a logical sleight-of-hand that eliminates an idea by redefining it as a conceptual error.

For the sake of my overall response I will temporarily grant you the premise that Rosenberg’s argument relies on a strong intuition that beliefs have intentionality.

…the intuition that beliefs are "about" something is the intuition that is used.

Even if it is, as you call it, an intuition, it is a particularly strong intuition. If you believe the opposite then you need a particularly strong argument to show it false.

…the reductio depends on accepting the truth of the intuition about beliefs, and not an explicit fact, …the reductio is an irrational argument and any implied conclusions about the relationship between brain states and beliefs becomes a non sequitur.

What you say is true. A strong intuition about what could be does not prove what actually is. The idea that beliefs have intentionality is highly predictive of human behavior. This gives it empirical justification, in addition to the deductive observations of Bertano on which intentionality is based. Another such strong intuition is that the physical universe is causally closed. This intuition comes from an empirical evaluation of science history and the intellectual preference for simple monist theories.

…this is an argument from ignorance and thus fails accordingly.

I would remind you that materialism makes a similar argument from ignorance. It says that since no means of interaction between the material and immaterial is known, then there cannot be any such interaction.

… his appears to be another case in which you rely uncritically upon the mind's own testimony about its contents.

Not at all. Your beliefs about the mind can be wrong, but you cannot doubt that you have beliefs. You consistently dismiss distinctions between the brute fact of qualitative experience itself and the quantitative contents of experience.

…if we are arguing about something outside of the mind, it's perfectly valid to rely on inter-subjective validity to carry the burden of proof.

Actually, we are not arguing about anything outside the mind. The issue at hand is the relationship between the semantic mental contents of the mind and physical body. As for the burden of proof, why do you believe it is invalid to make judgments about the behavior of others based on their stated mental processes, especially when it is confirmed by ones own inner experience?

…If … intentionality cannot be defined naturalistically, then premise 4/5 can never be made a rational fact; it will forever elude naturalistic definition and therefore…can never form the basis of a logical, rational argument.

That is exactly my point. Physicalism/naturalism and the intentionality of mental processes are mutually exclusive. Intentionality cannot be easily dismissed therefore you face a choice that cannot be rationally determined. That means that you have an existential choice between two very strong intuitions. Both views are, by your definition, equally irrational. And each view comes at a cost. In my opinion the cost of physicalism is nihilism. And that is a very steep price to pay for anyone who values the acquisition of knowledge.