2. FITTING OF FEELING TO FUNCTION – Why hunger is not thirst

Julia: Dan, you’re a philosopher, tell me how did nature fit our feelings to the functions they serve

Dan: Huh? How not? What’s your point?

Julia: Well, hunger – a feeling – makes us want to eat and thus to resupply energy consumed in living and to replace lost cellular material. Thus, eating serves an obvious biological need, but it is hunger that makes us eat. Why do we need hunger? Why isn’t the need enough? Notice how far conceptually hunger, as a type of thing, is from biological need as a type of thing; hunger is a feeling and need is something else, not a feeling but a condition, a requirement for something to happen, in this case a requirement to maintain biological homeostasis. Feelings and conditions are categorically different things. Yet the feeling of hunger is essential to the biological need to maintain homeostasis. The point is that hunger and need are separate ontological categories yet they form an inseparable biological pair.

Dan: You obviously have a story you want to tell. I hope it’s interesting.

Julia: Yes I have, and it is interesting. It’s a mystery but not a whodunit. It’s a story of self-deception and ultimately of revelation. The mystery is “Where do feelings come from?” and I do not mean in the sense of the neural correlates of feelings. We all know that the brain’s limbic system is the seat of feelings and emotions. I mean ontologically. What can feelings be that they are so plastic that evolution can fashion them to fit its biological needs, as in the example of hunger and nutrition? This is the mystery, and it is ancient. The self-deception part of the story is that the answer is in plain sight, but we have been unable or unwilling to recognize it as such. As for revelation, we come to that at the end.

Dan: Okay, perhaps you have spiked my interest. Proceed with your story.

Julia: First let me expand the plot. Think of other feeling/need parings: thirst and drinking to resupply water; fear and fight-or-flight to survive; anger and confrontation to maintain status; lust and sex to reproduce, and love and marriage to insure offspring survival. In each case feeling and need lie in ontologically different realms, yet they form inseparable biological pairs. Do you know what this means? Don’t answer; it means that we should reconstruct our ontological categories; we should take these feeling/need pairs to be ontologically united. This is the “hidden in plain sight” part.

Dan: Sounds profound. Is it?

Julia: I think so. To understand the point better, consider the absolute opposite situation in which feelings and needs are independent ontological kinds of things, each situated in its own ontological frame, as was once thought to be the case for metrical 3-D space and chronological time until special relativity united them into 4-D spacetime. If feelings and needs occupy independent realms of being, then evolution would have to coordinate them so that the feeling fits the need, that hunger, for example, does not cause us to drink when the body needs food, that fear does not cause us to confront when we should lie low. And where does evolution find these feelings anyway so that it can choose the appropriate one? We have here another version of the Cartesian mind-body problem.

Dan: Okay, I’ll test you on this. What is the Cartesian mind-body problem?

Julia: You know very well that in Descartes’ case the mind-body problem arises from his postulating that mind and body are categorically different things – mind consists of spiritual essence (a soul), body of physical essence (matter), a situation called Cartesian dualism. Mind has no mass and occupies no space. Body has mass and occupies space. How different can you get? The problem is that somehow the spiritual, unphysical mind must interact with the secular, physical body to make it move; this is, after all, how we do things in the world, by our minds commanding our bodies to move. In the present age where we all agree that it takes a physical force to move a physical mass, there is no room for a spiritual essence to take the place of a physical force and thereby to connect mind to body. Descartes had an out. The soul (mind) is God-given and so it can do things not doable by mere physical things. We lack this out. We are stuck with the mind-body problem in a thoroughly physical world with no supernatural escape.

Dan: Right, but we’ve been stuck with it for 400 years. So what’s new?

Julia: What’s new is the revelation to which I am coming, but first we must locate where feelings and needs meet physically, for here is where the revelation lies.

Dan: Let me guess; they meet physically in the brain.

Julia: Brilliant! Yes, of course, as already noted the limbic system in the brain is the physical thing responsible for feelings. But it is also responsible for identifying and broadcasting needs to the rest of the brain where the needs can be acted upon. For example, the part of the limbic system called the hypothalamus regulates hunger, thirst and sex drive. Take hunger. When the stomach determines it needs more food, it releases a hormone (ghrelin) into the blood that the hypothalamus senses, then sends a signal telling the rest of the brain to organize actions of the body that result in eating. We consciously experience this signal as hunger. And here is the point: there is nothing extra in the process to separately produce the feeling of hunger. The feeling of hunger is the same thing as the signal itself. In philosopher speak: the epistemological recognition that need and feeling are necessary paired implies ontological unity. A unity of the physical signal broadcasting the need for a response and the feeling that goes with that need. Thus, the problem with which we started of fitting a feeling to a need is automatically solved – feeling and need are two aspects of the same thing.

Dan: And what you say about hunger can be said of all the rest of the feeling/need pairs that you listed. A part of the body sends a chemical signal to the limbic system that it needs something, the limbic system then sends a signal telling the rest of the brain to organize the body’s actions to supply the need, and the action-inciting signal is the same thing as the feeling that we experience as the need.

Julia: Well done, A+. The ontological identity of feeling with biological need is, I think, the contribution that the fitting-of-feeling-to-need (FFN) problem makes to the mind-body problem. We deceive ourselves thinking that they must be ontologically distinct things. The FFN problem tells us that they must be the same despite the way we think about them.

Dan: Yours is not the first attempt to solve the mind-body problem.

Julia: No, and I am not the first to see the ontological identity of feeling and function. For example, the physicist Juan Roederer in his book Information and Its Role in Nature writes: “How a specific spatio-temporal neural activity distribution elicited by the sight of an object…becomes a specific mental image is an old question…I think that there is a radical answer. The pattern does not “become” anything – the specific distribution is the image!” (emphasis his). Notice he calls it a “radical answer”. Also I acknowledge that many attempts have been made to solve the mind-body problem within the framework of a world governed by the laws of physics with nothing extra. I will not review these attempts since you know them probably better than I do (anyway you can find them in Wikipedia). In shuffling through the list of proposed mind-body-problem solutions, I find one that is most compatible with the ontological unity of feeling and need. It is called “anomalous monism” (AM) proposed by Donald Davidson in a 1970 paper titled “Mental Events”.

Dan: I’ve heard of it but I’ve had no use for it. So remind me, what is anomalous monism?

Julia: “Monism” in AM means that mental events are identical with physical events – there is only one thing, but this one thing has two aspects, mental and physical. “Anomalous” means that under their mental aspect events are not describable by physical laws, and so in our law-governed physical world they are anomalous. Thus, if you didn’t already know, no law will tell you what hunger feels like, but because it is the mental side of the need to eat, you could predict that it exists and fits its purpose. This answers Thomas Nagel’s famous question: “What is it like to be a bat?” We know that echolocation feels like something, because it serves a function, but according to AM there is no rule-based method by which we could mentally experience the echolocation feeling. AM’s dual-aspect tactic in uniting mental and physical worlds looks like a modern version of Spinoza’s idea that all of existence has two aspects, extension and mind, these being two attributes of one thing, which he called God or Nature. Only, AM deals specifically with feelings aspect of Spinoza’s Mind.

Dan: Earlier you said that “the hypothalamus signals the rest of the brain to make the body do things to supply a need.” “Signal” is another word for information. Is this related at all to Giulio Tononi’s Integrated Information Theory (IIT), which is probably the hottest consciousness theory in current discussion. And by the way, Tononi explicitly ties consciousness ontologically to firing neurons, he calls it “A Provisional Manifesto.”

Julia: Yes, his IIT is like FFN in another way, too. A feeling like hunger in principle can be represented neurologically as integrated information, and IIT has a way to depict such a representation geometrically, thus giving a geometrical picture (multi-dimensional) of the hunger feeling. Here the analogy with FFN is that in FFN it is biological need that represents feeling while in IIT a geometrical shape represents feeling; but in neither case do we learn what the feeling is, that is, what it feels like. We know that it is but not what it is – knowing without knowledge, third person knowledge versus first person knowledge. This is profound. We can know that it is, but it is impossible to know what it is. We will return to this idea when we discuss Tononi’s IIT theory.

Dan: Great, but now I must leave. Next time I will have a question for you. I see a problem with your FFN solution to the mind-body problem.

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