The Conceptions of Belief Within the Brain


Though people use the term regularly, “believing” is a somewhat foggy notion in philosophy. It’s easy for a person to say that he or she has a belief, but saying what that even means is a completely different story; having a belief seems to be a very complicated endeavor from the analyst’s point of view. Jerry Fodor and Daniel Dennett are two contemporary philosophers who propose different accounts of what constitutes belief. Fodor takes up the phrase “propositional attitude” (or “PA”) to denote belief as a relationship a person can have with a proposition (325). If one believes something, then he or she is in a “belief-relation with that thing,” making belief a sort of interaction between two objects: person and proposition.  Other propositional attitudes are concepts like desiring and remembering, all of which Fodor calls “relations between organisms and internal representations” (325). In other words, Fodor ascribes to belief the characteristic of being represented inside one’s head as a sort of isolable fact..

Dennett, on the other hand, separates himself from such a view, which he calls “realist” (340).  To Dennett, belief is something that can be inferred over time rather than immediately pinned down. Dennett writes in the article “True Believers: The Intentional Strategy and Why It Works” that belief “can be discerned only from the point of view of one who adopts a certain predictive strategy, and its existence can be confirmed only by an assessment of the success of that strategy” (340).  Such a predictive strategy applies the concepts of “belief” and “desire” to real-world individuals as tools for predicting their behavior. The individuals that best manifest the strategy’s predictions are the prodigies of intentionality (the attribute of believing, desiring, etc.). The idea is that, after sufficient experimentation with the strategy, human beings will most succumb to the strategy while lawnmowers and lampshades will fail miserably. What is important to Dennett’s strategy is that the beliefs used to predict an individual’s behavior successfully are beliefs that one can objectively say the individual has. Thus, like Fodor, Dennett claims that beliefs are objective. However, he claims that their existence fully fleshes out only after the fact. Belief, in this sense, is something that takes time and is observed externally because its attribution is just an abstract way of analyzing events and behavior (though, an objective one).

But, this is where Fodor’s position seems to beat Dennett’s. While Dennett has a point in proposing a versatile conception of belief – one that can apply to anything physical, successfully or unsuccessfully – it is still unconvincing that belief’s very structure might not necessarily be represented semantically in the brain. If a person “believes” something (or, as Dennett would say, acts in a way predictable by belief attribution), how could he or she believe it (or act that way) by virtue of anything other than the organ that produces behavior – that is, the brain?

To determine the exact nature of propositional attitudes, Fodor outlines five postulates about them that he considers to be self-evident in his article “Propositional Attitudes.” These postulates all aim at the eventual conclusion that the objects of propositional attitudes (what it is that one can believe) have important similarities to natural language (i.e., English). As Fodor eventually says, “the general characteristics of propositional attitudes appear to demand sentence-like entities to be their objects” (334). Thus, when one has a propositional attitude, one literally has a “sentence-like” entity. Fortunately for Dennett’s position, the argument that belief exists in the abstract characterization of previous events still seems to present an account of belief that meets Fodor’s criteria. Dennett, on the other hand, would simply say that the postulates are true by virtue of their usefulness in describing the beliefs that can be attributed after the fact. That is, the beliefs attributed to someone through a predictive strategy would have the same qualifications as Fodor’s propositional attitudes because a person contains a “sentence-like” entity in the sense that saying so leads to success. A person could be said to contain a belief when that belief accounts for their behavior. In no way would Dennett specify, however, that the person contains it within his or her cranium. Saying so is not necessary in order to be consistent with Fodor’s postulates, notably because the postulates themselves don’t really say anything about physical representation.

First, Fodor states: “propositional attitudes should be analyzed as relations. In particular, the verb in a sentence like ‘John believes it’s raining’ expresses a relation between John and something else” (325).  Well, by the predictive strategy, the specific relation could be construed as, say, acts in accordance with. That is, John will behave according to the statement “it’s raining,” and later on, after he has done so, you can point it out. Second, Fodor says, “A theory of PAs should explain the parallelism between verbs of PA and verbs of saying…. the things we can be said to believe… are the things that we can be said to say…” (327). By Dennett’s strategy, the beliefs one can successfully attribute are perfectly sayable because their vocalization is really the only way they exist. They are propositions one can be said to believe if doing so is productive. At one point, Dennett says, “all there is to being a true believer is being a system whose behavior is reliably predictable via the intentional strategy, and hence all there is to really and truly believing that p (for any proposition p) is being an intentional system for which p occurs as a belief in the best (most productive) interpretation” (346). Thus, it is practically inevitable for Dennett’s account to give belief the form of a sentence, which is then treated as a type of abstract object, because it is part of the predictive strategy’s definition to be implemented through language. At this point, the other postulates are somewhat irrelevant, given what they all point to (according to Fodor). The important idea is that propositional attitudes are sentence-like whether one considers them to be instantiated in the brain (like Fodor does) or instantiated in some abstract analysis of events (like Dennett does). The debate, then, isn’t settled at the level of Fodor’s postulates. However, this fact suggests that Dennett’s predictive strategy, something purely linguistic (as has been shown), seems to necessitate linguistic origins in order to work. In other words, the cause of the behavior that can be reliably analyzed in terms of propositional attitudes must reliably produce such behavior. But, then why not take out the extra step of analyzing the behavior according to propositional attitudes and go right to the cause itself – the brain.

Toward the end of his article, Dennett attempts to explain why a predictive strategy works. He brings up Fodor’s idea that beliefs in all their formality are somehow inside someone’s head: “A currently more popular explanation is… for each predictively attributable belief, there will be a functionally salient internal state of the machinery, decomposable into functional parts in just about the same way the sentence expressing the belief is decomposable into parts…” (348). However, he claims the following: “Those who think that it is obvious, or inevitable, that such a theory will prove true (and there are many who do), are confusing two different empirical claims. The first is that intentional stance descriptions yield an objective, real pattern in the world… The second is that this real pattern is produced by another real pattern roughly isomorphic to it within the brains of intelligent creatures” (348-349). This is where Dennett crucially departs from Fodor, and it is where he seems to be wrong. Fodor might actually concur on the point that the claim of an objective intentional stance does not directly imply an objective isomorphism in the brain. After all, he does say, “the theory that propositional attitudes are relations to internal representations is a piece of empirical psychology, not an analysis” (336). In fact, Fodor gets his point of view from empirical examples such as the ability of the mind to parse English sentences (335).  In a sense, it seems that the departure from Dennett is incidental – an artifact of empirical psychology. In that case, it would seem that Fodor is wrong too.

For, one would think that, if a predictive strategy works, it works because certain behavior is letting it work. And, certain behavior, it can be assumed, is caused by certain brain states. In that case, there is an indirect route from brain state to belief through the medium of behavior analyzable in terms of beliefs. Thus, belief is perfectly functional of brain processes in any way the term is used. But, as has been said, belief can only be talked about in terms of propositions (whether these propositions are taken to be brain states or tools for making predictions). Thus, there is effective mapping of brain processes onto propositions simply by discerning the behavior with which these brain processes line up. It seems as though there could be nothing else but a “language of thought,” as Dennett calls it (348). This language of thought dictates what one does, which is then analyzable to determine the beliefs instantiated in the language itself. To be intentional is to carry one’s intentionality around wherever one goes.


Works Cited

Dennett, Daniel C. “True Believers: The intentional Strategy and Why it Works.” The Nature of Mind. Ed. David M. Rosenthal. New York: Oxford University Press, 1991. 339-49.

Fodor, J.A. “Propositional Attitudes.” The Nature of Mind. Ed. David M. Rosenthal. New York: Oxford University Press, 1991. 325-38.


Julian Grove (’10) is a Cognitive Science major at Johns Hopkins University.

2 thoughts on “The Conceptions of Belief Within the Brain

  1. I apologize at the beginning if I completely miss the point of the article or if I come across as a jack-off. It is not my intent as I found this article extremely interesting and my lengthy comment is meant as a compliment to the author.

    That said, I feel I must have missed something because it is not clear to me how the author defends her main point or even exactly what the main point is. If I’m not mistaken, it would seem that the author is claiming that both Fodor and Dennett are wrong if they are skeptical of propositional attitudes about belief being reducible (or at least isomorphic) to processes in the brain. The author claims, “certain behavior, it can be assumed,[are]caused by certain brain states.” It seems then that the author takes it to be unquestionably true that the nature of belief must be reducible to the operations of particular brain processes. Dennett’s skepticism is met with the remark “he seems to be wrong” and Fodor’s implicit agreement with Dennett is met with “in that case, it would seem Fodor is wrong too.”

    But why are they wrong? Because they do not agree with an assumption of cognitive science? And indeed, it is an assumption and one that I do not feel has been argued for at all in this paper. The author writes at the end, “There is effective mapping of brain processes onto propositions simply by discerning the behavior with which these brain processes line up.” This means that for any behavior we can observe we are justified in thinking there is a corresponding brain process. Why should we assume that? If it can be shown that there is a disconnect between behavior and brain process then we will see that the one does not necessarily reduce to the other.

    Why isn’t it the case that perhaps certain brain states, like belief, though caused by the brain, cannot be reducible to a specific brain process? If there is a brain process which acts like a program that manipulates sentences in the brain and these manipulations are my beliefs, then it follows that the human being who never developed language has no beliefs, and for that matter, neither do animals, even those that are arguably very close to us in intelligence and who exhibit behavior that looks like belief behavior (chimps and dolphins). So what happens here is that there is belief-like behavior that is not mapping onto our brain process because these examples do not have sentence-like entities in the brain. Chimps do not have the sentence “It is raining” in their brains, but they do have a belief that it is raining. But if we assume that every belief is a product of a brain process analogous to ours then it seems we are concluding that the examples have no beliefs even though they exhibit the behavior. And if our behavior and our brain processes must be mappable, then this is evidence either that 1) beliefs are states that are not reducible to brain processes, which would allow for the possibility that chimps have beliefs, or else 2) chimps have different brain processes that allow them to form beliefs without sentences or sentence-like entities. And the question would then be: if they can have beliefs without this sentence-like brain process, why can’t we? If we can hypothesize two plausible brain processes on belief, one that includes sentence-like entities and one that does not, and both can explain the behavior, how are we to decide which one is true? It seems as if we can get away with just explaining belief as an analysis of intentionality or behavior or whatever without ever having to assume that there is a corresponding brain process. And we can do this while still maintaining that beliefs are caused by the brain.

    If all that the author is claiming is that the true nature of belief must take into account that any belief is caused by the brain then I agree. But if she is claiming that Dennett and Fodor are wrong about belief if they are skeptical about them being reducible to brain processes, then I think I have been given only assertions to that fact and not an argument.

  2. Wow…

    I am a complete @$$ and apologize for thinking you were a woman. So so sorry Julian. I’ve been up all night and haven’t slept in 48 hours so I hope that is excuse enough. Again so sorry Julian.

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