The dizzying free fall of QBism

In conversation with Prof. Christopher A. Fuchs, Essentia Foundation's Hans Busstra explores QBism: an interpretation of quantum mechanics that puts the agent right at the centre. QBism regards quantum theory as just a ‘tool’ agents use and disclaims ontic interpretations of Schrödinger's wave function: the quantum state is not something ‘real,' but instead just our description of, or even our beliefs about, nature. Once known as Quantum Bayesianism, Fuchs has redefined QBism more radically as: 'Quantum Bettabilitarianism.' As agents, we make ‘bets’ on the behavior of the universe in its interactions with us.

Though QBism does not equal analytical idealism, in this conversation we touch upon a striking similarity: namely, that pure experience (i.e. phenomenal consciousness) is what quantum theory points to as fundamental in nature. And this, in turn, has implications for how we look upon the meaning of life. In Fuchs' words: quantum theory gives meaning to life.

00:00 Introduction
01:30 Some opening remarks on experience and 'nature striking back'
04:27 Chris Fuchs on the definition of QBism
05:12 Was Copernicus wrong? Why QBism is a free fall
06:46 On Cubism in art and QBism in quantum theory
09:24 The metaphysical debate within quantum mechanics
11:04 What is QBism?
14:23 We bet on the behavior of the universe with us
15:51 What is an agent, an observer, a decision maker?
16:53 Quantum theory is just a manual that agents use
18:10 Chris Fuchs on his mentor John Wheeler
20:24 The participatory universe
20:57 The broken glass between observer and observed
21:50 There is no physical reality prior to measurement
22:18 Back in the quantum museum...
23:37 Chris Fuchs on the different interpretations of the wave function
25:02 Agents perform 'actions': measurement is a term we shouldn't use anymore
26:29 Must an electron 'obey' our gambles on it?
27:36 The multiverse is a dead universe
30:05 The many worlds interpretation wants to uphold determinism
32:03 Genuine novelty comes into the world, the universe is being created on the fly
33:02 From the abstract to the concrete: QBism in practice
38:16 Is QBism doing best in progressing quantum physics?
41:47 The solipsist critique: how to account for a shared world?
44:33 Order in the universe is placed there by us, by the human mind
45:38 What is the ontology of QBism?
47:24 The stuff of the world is neither mind nor matter
50:21 QBism in relationship to analytical idealism
53:06 Can quantum mechanics tell us something about the meaning of life?
58:09 A personal conclusion of the interviewer

For more video's on QBism here's a playlist:

[markcounseling]

I didn't expect that this would be so profound or that I would get such wonderful advice from this physicist about living. That distinctions, difference (in experience) and not generalities (in thought) are key. That "a lot of the business of thinking clearly is finding the right words" -- one of Wheelers obsessions as well. And linking QM to meaning and value: Brilliant!

James' essay The Will To Believe saved my life, I would say, long ago at 19. "My first act of free will shall be to believe in free will" -- I held on to that phrase like a talisman in those dark days. I studied Physics, but didn't put the two together. Who did in the 80s? But here I get it from Dr. Fuchs. 🤩

I LOVED this episode, thank you!

[rooruffneck]

I really liked this. While I fully understand why Essentia needs to produce some much more technical conversations that only real physicists can truely grasp, this video is what I'm hungry for. I want to better understand the main gist of the different quantum interpretations. Fuchs does a wonderful job in this video, along with Hans' helpful framing. I'm very excited about this series. Here is my greedy suggestion: would it be possible to have a short conversation with Bernardo about each video, just relaxed reflections he has on what gets covered in the video?

I was surprised at the end to realize that when pressed to speak about his metaphysics, everything Fuchs said fits an analytical idealist frame. His reason for not wanting to use the word 'Consciousness' is simply because it often entails human cognitive forms of experience. But he sounds very happy placing mentality (experience, sensation...) at the ground floor.

[roelofvuurboom]

In my view, thinking is modelling. They are one and the same. When we think about "something out there", we - of necessity - abstract, i.e. ignore, a myriad details about that "something". As Fuchs says, if we ignore the right details then we may find that our models of various "somethings" may be similar. The models we create are, of necessity, abstracted and thus, of necessity, incomplete descriptions of reality (the "something out there").  A well known expression is that the map is not the territory. The above statements are really saying we are only ever capable of thinking about maps of the territory because thinking *means* creating a map.

If we choose our models carefully i.e. ignore the right set of details we may find that the models are similar or identical for those parts of "something out there" that we are examining. In that case, we say there is a "law of nature" and that "nature" or "reality" or the "something out there" is obeying that law. Of course, nothing is being obeyed, The "law" is not "dictating" how nature works. It simply reflects our ability to abstract away (ignore) certain differences which we call details which we then call "unimportant" such that the model that remains demonstrates a similarity for the parts of reality that we are exploring. 

It is *we* who decide what details are important or unimportant and so what details to ignore or not ignore. That decision is a judgement based on *our* experience and thus our humanity. So in that sense, it is *we* who decide what laws come into being or not. They are inextricably linked to us or to be more accurate they are inextricably linked to our acts of thinking. If other life forms think as we do (i.e. by modelling) they might come up with the same laws too. 

If we believe thinking is a universal property of intelligent life forms and that these life forms often make the same judgement calls about what details are considered important or not, we might then make the statement that the laws are "universal". But the universality of the laws has nothing to do with reality itself but is a statement or belief about the universality of the property we believe thinking life forms might have. Reality - as opposed to models of reality - has no laws because reality does not abstract i.e. ignore details of itself.

QBism asserts that the actions of the agent influence reality. That is certainly true but I suspect that it is understanding the very act of thinking and its implications as outlined above that really forms the cornerstone of QBistic philosophy.

While we can never *know* all details of reality we certainly can *understand* aspects of reality because understanding by its very definition means having models of aspects of reality that we find provides us with - for us - useful results.

[FootnotesPlato]

Thanks for this really helpful intro into Fuchs. I clearly need to read him asap. Wonderful to hear how deeply he has drunk from the Jamesian well of pure experience, and his familiarity with Whitehead. Materialism is dead, but there remain important distinctions to make between idealism (whether absolute or analytic) and panexperientialism. Let me know if you want to talk more about the latter 😃

[JohnSmall]

Excellent, I really enjoyed that. I've read all Chris Fuch's papers, but never seen him talking. Very nice

[kevinceney]

Excellent video and pitched at just the right level for me.
Thank you

[Togetherland]

It would be great to have a relaxed roundtable with Fuchs, Spira, Hoffman and Kastrup and Swami Sarviprinanda (wrong spelling).

[nowenterpsie]

Beautifully closed with that wise nod to the deep relevance of our existence as experiencers. Excellent discussion.

[bunberrier]

It reminds me of a couple passages from the Bible.
In the beginning the world is formless and void, and the spirit moves upon the waters. Then he makes stuff. This is similar in form to an observer looking at probabilities, which then manifest. And it also says we are like God, made in his image. So we too can observe this sea and manifest things.

[RandallLeeReetz]

What damage must happen in a person's childhood that makes hard relativistic (the observer as central) interpretations of reality attractive?

[jorgeruiz]

Someone or something above the human mind gave us a game board and we made up the rules as we played

[sarah-ismail]

Wouahou, Wouahou, Wouahou. Big heavy video. Chris Fuchs Qbist interpretation is giant and you did a fantastic work. Thank you so much. Bravo so much. no words.

[MikhailKutuzov-wxgy]

Does "consciousness" continue to be a misleading term for QBism, or in general? It seems to give us this image of Cartesian mind-as-its-own-substance, when the “phenomenal consciousness” of James, Whitehead, or German Idealism has very little to do with that.

1. If you hold onto this simplistic picture where we “have” consciousness and there is some kind of barrier between knowledge of our own minds-perceptions-sensations and that of the external world, then solipsism is a genuine philosophical problem for you. You’re going to take seriously the possibility that the only knowledge you have of the external world is really your own mind since that’s what you’ve got epistemic access to. Ironically or not, the picture of mind-cognitive interface-world tends to protect the problem of the existence of other minds.

2. The idealists tend to attack solipsism on the grounds that their problem is framed entirely by the possibility of eternal illusion. As long as you believe subjects don’t have access to nature, then anything we say about it is cloaked or dimmed by skepticism, solipsism. Transcendental idealists like Kant have the most in common with the picture above (although he critiqued transcendental realism too), but no matter what strand of idealism you subscribe to, you’re not going to be upset by the pleas of solipsism that want to argue the world does not exist. The idealism Friedrich Hegel talks about in the Phenomenology of Spirit, and the pragmatism of William James do not put a metaphysical blockade between the knower and the known. This leads to a completely different strategy for critiquing solipsism. The idealist or the pragmatist could be seen as arguing that the person troubled by the idea that all our knowledge is an illusion is mistaken because they have not sufficiently motivated the existence of this barrier to knowledge. They have not shown by all of us at once should doubt the existence of others.

3. You could call this an advantage of the idealist position, but note that in the view, the sense of “consciousness” is completely different from the property of mind trapped in a corporeal vessel. The sense of “phenomena” Fuchs is getting is what William James recast as a “relation” from which we differentiate subjects and objects. “Consciousness” or the “ego-pole of observation” is one such differentiation or “experience catching sight of itself.” The consciousness you refer to in everyday conversation is more like the “subjectification” of the subject or “personal identity.” And if you agree with Fuchs that idealism’s connotation of “literal thought being put in nature” is too strong, then you’re going to resist the idea of "pan-psychism" on the grounds that it is no more satisfying than the simplistic view above. Both the simplistic realism that entices skepticism and the literal idealism of "mind-in-matter" already presume the intelligibility and correctness of subject-object dualism.

4. Fuchs seems to take that James was right to reject this dualism. The ability to cast phenomena in some particular ontological light, a point discussed by Fuchs at 47:24, makes me think that the QBist move refrains from settling on a strict ontological interpretation or differentiation of ontologies into “matter” or “mind.” The reason you might go for this idea is because physics does not have to posit the nature of the physical object to do physics – one simply does it.

Also, in addition to James, Whitehead, and others, another philosopher you might throw into the mix then is Ernst Cassirer – the neoKantian.

[Bolaniullen]

48:19 this guy only needs to hear Bernardo talk about meta-congnition and the distinction between it and ''raw''mind and he will be an idealist, im pretty impressed by this guy. Much more than any Bayesians i have talked to in real life

[pettiprue]

As a child I knew that what I was looking at only popped up when I was looking at it. I tried to "catch it", sneak up on it. Suffice to say I couldn't. I eventually forgot about my sense reality until the I saw on youtube the double slit experiment. BOOM. Beautiful video. Thank you X

[FrankJIvins]

I like this far more than the plain posted seminars. They are usually too dense for me to enjoy. But, with this, you've put one of those talks in context. Rally fun!

[Johan-burx]

"(The) Living is always a fresh forming¨ Eugene T. Gendlin

[GriefGrowth]

Comment about the level of material you should produce. I think you should always go over the basics quickly. It's better to skip ahead for those who are familiar with the material than for those who aren't familiar to be lost.

[SageCog-zlue]

In an infinite dimensional complex vector space such as a Hilbert space then ever possible state space or vector space can exist.

Gyrovector spaces are collections of Lorentz transform velocities called boosts.

[MKHobson]

Thank you for this thoughtful and beautifully-constructed discourse. You mentioned solipsism a couple of times in this episode. It seems always to be dismissed as a philosophical non-starter, but I have never been able to understand how it is not the fundamental "answer" that solves the materialist conundrum. Solipsism and idealism seem intertwined to me, or at least compatible. I would very much enjoy seeing you tackle this concept.