(No reason. Just wondering if I'm the only person around here who...)
Thought Criminal quotes:
Now, you may complain that this is not what you mean by “existence”. You may insist that you want to know whether it is “real” or “true”. I do not know what it means for something to be “real” or “true.” You will have to consult a philosopher on that. They will offer you a variety of options, that you may or may not find plausible.
A lot of scientists, for example, subscribe knowingly or unknowingly to a philosophy called “realism” which means that they believe a successful theory is not merely a tool to obtain predictions, but that its elements have an additional property that you can call “true” or “real”. I am loosely speaking here, because there several variants of realism. But they have in common that the elements of the theory are more than just tools.
And this is all well and fine, but realism is a philosophy. It’s a belief system, and science does not tell you whether it is correct.
Sabine Hossenfelder: Does The Higgs Boson Exist*
I would not equate philosophy with a "belief system," especially since most people think of belief and faith as synonyms, and faith, as William James quoted the apocryphal school boy defining it, is "believing something you know ain't so." Yes, realism is a philosophy. So is science, as Kuhn pointed out (nothing Hume hadn't already said, and his philosophy was empiricism, the philosophy that is the very framework and construct of science). But don't tell a scientist that. It makes them as upset as pointing out to a "believing Christian" that their Christianity is a theological construct. I got tired of having that conversation, and finally figured out it's really not up to me to change minds on the subject. Or even to explain myself.
And no, science doesn't tell you a philosophy is "correct," for the same reason Godel's theorem of incompleteness established that Russell and Whitehead's Principia Mathematica couldn't establish a set of mathematically based equations which would answer all philosophical propositions: because a formal system (like science) can always generate questions to which that system cannot provide answers. So philosophy can't answer all of your questions, either; but it can answer questions science cannot. But that doesn't make philosophy a "belief system," either. And belief is not contrary to science.
I heard an interestingly simple (probably too simple) explanation of the multiple-universe theory of phsyics, the one from which popular culture drew the idea that every action, every decision, creates a new universe in which that decision was not taken, or was made another way. I can't do the physics justice at all, or the math; and I may even have the details of the explanation (this was on "This American Life") completely correct as read, either. But basically mathematics has established that, at the quantum level, particles (something, anyway) go in two directions at once. Let's say opposite directions. So let's say the particle is in motion, strikes an object, and that collision redirects the direction of the particle. But the same particle goes in two directions, at the same time; without splitting or reproducing or fragmenting or any change in the physical state of the particle. That part is key: the particle is unchanged, but the particle goes in two directions at once. This, you understand, is established by the mathematics of quantum mechanics.
So, the story continues, a particle accelerator was set up, and particles hurled at the speeds necessary to observe this quantum level phenomenon, but the particles didn't cooperate. They went in only one direction; not two. One way, or the other; not both/and. A small group of physicists (not a majority, reportedly) decided the solution was that, in another universe, created at the moment the particle struck, the particle went in the opposite direction. It was, it seems, the only way to preserve the math. Which had to be right, so something wholly apart from human experience must have happened.
Which sounds like a faith claim to me. Indeed, I can't find an argument that distinguishes it from one; well, not a sound argument, anyway.
Back to the Eddington, Section IV
The mathematical theory of structure is the answer of modern physics to a question which has profoundly vexed philosophers.
"But if I never know directly events in the external world, but only their alleged effects on my brain, and if I never know my brain except in terms of its alleged effects on my brain, I can only reiterate in bewilderment my original questions: "What sort of thing is it that I know" and "Where is it?"
C.E.M. Joad, Aristotelian Society, Supp. vol IX, p 137
What sort of thing is it that I know? The answer is structure. To be quite precise, it is structure of the kind defined and investigated in the mathematical theory of groups.
It is right that the importance and difficulty of the question should be emphasized. But I think that many prominent philosophers, under the impression that they have set the physicists an insoluble conundrum, make it an excuse to turn their backs on the external world of physics and welter in a barren realism which is a negation of all that physical science has accomplished in unraveling the complexity of sensory experience. The mathematical physicist, however, welcomes the question as one falling especially within his province, in which his specialized knowledge may be of service to the general advancement of philosophy.
The phrase "if I never know my brain except in terms of its alleged effects on my brain" vividly, if not altogether accurately,* describes the conditions under which we labour. But it is not very alarming to the physicist, whose subject abounds with this kind of cyclic dependence. We only know an electric force by its effects on an electric charge; and we only know electric charges in terms of the electric forces they produce. It has long been evident that this is no bar to knowledge; but it is only recently that the systematic method of formulating such knowledge in terms of group-structure has become a recognized procedure in physical theory.
* A more accurate form would be: if I never know any brain except in terms of its alleged effects on a brain." [N. B. Eddington's footnote, not mine.]The bewilderment of the philosophers evidently arises from a belief that, if we start from zero, any knowledge of the external world must begin with the assumption that a sensation makes us aware of something in the external world - something differing from the sensation itself because it is non-mental. But knowledge of the physical universe does not begin in that way. One sensation (divorced from knowledge already obtained by other sensations) tells us nothing; it does not even hint at anything outside of the consciousness in which it occurs. The starting point* of physical science is knowledge of the group-structure of a set of sensations in a consciousness. When these fragments of structure, contributed at various times and by various individuals, have been collated and represented according to the forms of thought that we have discussed, and when the gaps have been filled by an inferred structure depending on the regularities discovered i the directly known portions, we obtain the structure known as the physical universe.
Eddington is going after empiricism, specifically Hume's empericism, though he may not know it. Hume posited what I call, living in the 21st century and not the 18th, the TV set theory of consciousness. That is, Hume says since we cannot directly observe consciousness, we cannot really know what it is. And since empiricism won't allow of the 'ghost in the machine' (a criticism of Cartesian dualism, not an explanation of it), how can the input of the senses be observed? Hume says the input of the senses themselves are human consciousness, because those inputs are sent to the brain where they are...well, received. And being received they are turned into knowledge; they are understood; simply by being received (perceived) in the brain. Which seems to be like saying the TV is running in the empty room with no one there to watch it, but still the signal translated into sound and pictures is perceived by....what, exactly? How does the room know what is on the TV? How does it understand? Where is the interplay of memory and sensation that empiricism (going back to Locke) argues is the source of our knowledge and understanding (trying to abandon the original dualism of Plato, to whom Cartesian dualism is indeed just a footnote).
Eddington, I have to point out, sidesteps Hume by going back to Descartes, essentially. "I think, therefore I am" requires a pre-existing consciousness which can do the thinking. How that consciousness is able to think, what materials (I use the term metaphorically) it uses to build knowledge, was a problem that vexed both Plato and Locke (and Hume). Plato posited a soul that had the knowledge but, in another 21st century metaphor, had its hard drive fragmented by existence (i.e., birth) and lost access to the data stored there. It's still there, but education is a process of recovering it (this does lend itself to ideas about reincarnation, but we don't need to go there). Locke tried to throw that out, and posited a tabula rasa (a metaphor but also a construct; a floor wax and a dessert topping) upon which experience writes, and the collection of these experiences becomes consciousness. But if that were so, babies would take decades to learn language (where would they start to understand those sounds were words, were ideas, were language with a vocabulary and a grammar?). Instead, they do it in a period of months. (Plato would say they can do this because they recover the knowledge, but that hardly seems satisfactory.) The analogous process is music: a rare few children can play music from a very, very young age. Others, introduced to music, take to it like a duck to water. Still others have no musical ability at all, or what they do have takes immense training to bring them barely to competence. But any child, absent physical impairment, can take up language in very short order, and while music is complex at one level, simple at another, there is no known human language any less or more complex than any other.
So how do we learn it so quickly? Especially when only some of us are good at math, or music, or science? But all of us can communicate (the fundamental purpose of it) in a language?
The starting point of physical science is knowledge of the group-structure of a set of sensations in a consciousness.
Eddington avers he means the "logical starting point," but his logic presumes a fact not necessarily in evidence. What is consciousness? How do we define it? Must it be apparent to us? It is, in common parlance, something we can lose; but when we say that, we expect it to be soon regained. What, then, of coma patients? Until we had a concept for them, an idea of the comatose state (which science defines, but not that well. Heartbeat? That was one. Now it's "brain activity." But we only mean electrical activity. And science doesn't get the final word. Recall the poor young woman who, 20 years ago, was in a vegetative state. Science said her brain had liquefied. Her family insisted she was still alive, still had "consciousness". It was a heartrending case, but the legal issues were real: who gets to decide? You may say she didn't want to live that way. But without consciousness, did she have any wants? And is consciousness lodged in the brain? Where? What is it, from what does it arise, where does it come from, where does it go? Aren't we back to the "ghost in the machine"?) was impossible to imagine.** Rather, I suppose, like understanding how a particle can be driven into going in two directions at the same time. If a comatose patient never regains "consciousness" (this time the state of being awake, responsive, able to at least respond to verbal stimuli), have they lost it forever? We don't know in every case, which is why we keep comatose patients "alive" for as long as possible (by 'alive' I mean do what is necessary to sustain physical life functions). To do otherwise would be to destroy their consciousness; and by that we mean kill them.
What, then, of Alzheimer's patients? I've seen them in such a state they cannot respond to any stimuli, except apparently the stimuli of being alive. Do they still have consciousness? It is not one we can reach, by any means. But we do not kill them, either. We care for them. We let them reach a natural (as opposed to induced) death. Maybe we even stave that off as long as possible; maybe not. But do they still have a consciousness? Or is it merely a by-product of brain function, and a brain so severely impaired by the physical processes of Alzheimer's is incapable of creating or sustaining it? If so, the mystery is not solved: how does this 'consciousness' come to be so complex, so fundamental to human existence? How does it acquire language? People rendered unconscious have been known to babble in languages they have studied, if they are multi-lingual; or to recite familiar prayers automatically. Are consciousness and language inextricably linked? Well, how else do we know consciousness, except through language? And yet we don't consider those shorn of language, or who were never able to develop it, as having lost consciousness and therefore identity, humanity, even knowledge. I've known severe autism patients who display knowledge of a sort, even though they have no language skills at all.
When these fragments of structure, contributed at various times and by various individuals, have been collated and represented according to the forms of thought that we have discussed, and when the gaps have been filled by an inferred structure depending on the regularities discovered i the directly known portions, we obtain the structure known as the physical universe.
Do we? And how do we know that? I mean in the philisophical sense of what knowledge is; I mean in terms of epistemology. Because frankly, even in Eddington's description, I can't separate it from a description of a belief system.
It's not just the philosophers who are bewildered.
*I am aware I've jumped past the question of existence that begins this quote. You don't even want to get me started on the question of existence, though
**Is consciousness even lodged in the brain? We say so, but we also speak of the heart (the Greeks thought it was the liver) as the place where emotions reside. That's metaphorical, of course; we know better than that. But we think consciousness is in the brain because if we damage the brain, the individual can lose the ability to communicate. If you can't communicate, do you still have consciousness? Are you trapped in your body, then? That was a popular vision of some story telling (Trumbo's Johnny Got His Gun springs to mind), and the fear of being "trapped" in your body prompted a lot of support for euthanasia. Certainly death is the final loss of consciousness, and beheading is the ultimate separation of body and brain. But is death because the seat of consciousness is lost, or because of the physical shock and inability of the body to sustain functions after such a trauma? If we don't know what consciousness is, how can we be sure where it is?