Round Table Talk:

Dialogue Between a Philosopher and Physicists
Markus Gabriel

Professor, Director of the International Center for Philosophy, Bonn University

Hitoshi Murayama

Kavli IPMU Principal Investigator, and Professor, UC Berkeley

Yasunori Nomura

Kavli IPMU Principal Investigator, and Professor, UC Berkeley

Physicists Talk about
What Science Is
Murayama: I would like to thankMarkus for joining us for thisconversation shortly after yourlecture.＊1 In our earlier conversation
you pointed out that, precisely
speaking, what people usually
attribute to Popper is not what heactually said. So, one thing we can gofor is to repeat my understanding of
how science is defined according to
Popper, though it might not be what
Popper actually said. Then, we candiscuss what is your real response
is on this definition. Is that the rightthing to talk about?
Gabriel: Why not? That makes sense.
Murayama: So, first of all, we arescientists and we have been taught
in a specific way what science isabout, how it should be conducted,
and sometimes we find it very
constraining. That sort of the narrow
definition, which we normally＊1

On June 11, 2018, Markus Gabriel gave atalk entitled Science and Metaphysics at
Kavli IPMU and IRCN joint seminar held at theFaculty of Medicine Experimental Research
Bldg., on the University of Tokyoʼs Hongo
campus. This round table discussion was held
after the joint seminar.

12

Markus Gabriel

Hitoshi Murayama

attribute to Popper and whichscientists agree, is not really what wewould like to do sometimes, especiallywhen we talk about big questions
about the universe and so on. So,thatʼs why I would like to get yourinput on what we think the definitionof science is in a traditional sense andwhat kind of other thinking is goingon in the philosophy of science in thepast and what your take is on thisquestion. So, thatʼs one thing we cantalk about.
Nomura: In fact, Hitoshi, do you andme completely agree? Maybe not.
Murayama: Yeah, weʼll see.
Gabriel: Maybe both of you try to juststate what you think science is, andthen I map this onto a philosophicalconceptual space.
Murayama: Okay. Here is, I think,what I was taught in elementary
school what science is about. The

Kavli IPMU News No. 45 March 2019

Yasunori Nomura

science is about trying to understandthe phenomena around us. To
understand this, of course we needto take quantitative data on what ishappening around us, and once wehave quantitative data, you come up
with a theory that tries to explain
those data.
Once you have a theory that is
successful enough to explain all
the data youʼve got, then you start
making further predictions out of thetheory and then confront new set ofdata to see if those predictions willagree with the new set of data, and ifthey donʼt, you say, Aha, I falsify thistheory, and this is the process, which
we were taught, I thought by Popper,
as the definition of science.
Now, if it does succeed to explain
the new set of data, then you say,
Okay, my theory is consistent withdata. I would never say my theory

is true. Then, you repeat the processuntil you hit the point that is again
falsified. Then, you change yourtheory and then try to, again, address
all the data we have explained before
to see if that success is still retained,
and if it is, then you make further
prediction and then start taking
data again and compare that to thedata to see the theory is still right orwrong. Again, you never say itʼs righteven if it is consistent with the data.
You only say itʼs wrong if it does not
explain the data, and then you try
to expand the theory further. This is
the process we are taught of what
science is about.
Nomura: I think that’s agreeable.
I think no scientist can say that I
disagree.
Murayama: Okay. Maybe some twist?
Nomura: Yeah, small ones. One
thing is that you said we never say
something is true. Indeed, people
sometimes make a statement like
Newtonian Dynamics is wrong
because of the fact that thereal dynamics is, at least, special
relativity. I think such a statement ismisleading. Of course, this is a kindof language issue and in scientistʼs
approach, it doesnʼt matter. I mean,
we donʼt care if someone wants
to say that Newtonian dynamics iswrong because of special relativity,or if someone says that Newtonianmechanics is true because it explains
phenomena very well in a certain
regime. The fact is that you must first
define the word true. We can use
this word to mean contemporary
truth, and then Newtonian dynamics
was certainly true, at least in the
19th century. Similarly, we can use
the word to mean true in a certain
regime for all practical purposes. In
this sense Newtonian dynamics is stilltrue now.

Anyway, I think the basic attitudeof science is always like that. We
donʼt care any language issues, aslong as we understand what we aretalking about. In this case I donʼt care
if you say the theory is true or wrong.
The fact is only that the theory
applies in a certain regime incertain precision. In some extreme
cases, however, it may become
obvious that the theory is simply anapproximation of another theory̶
in the case of Newtonian dynamics
the special relativity̶and then wemust consider this new theory if wewant to describe these cases. To me,
this way of thinking is one way todefine science. In this sense, scienceis very operational. Having said that,the definition of science, at least
natural science, also includes theprocess of trying to explain the same
set of data by the smallest number ofassumptions. In fact, this last point isimportant because otherwise you canjust list all the data to describe Natureand call the list a theory.
Murayama: Thatʼs right. You can have
one theory for every single data.
Nomura: Yes, that is the worst formof theory. Then you try to minimize
the number of assumptions fromthere, and then your theory will
have an explanatory power. Sucha theory usually makes predictions,
namely it does not only reproduce
what you already observed but also
something else̶as Hitoshi said; Iʼmjust repeating it here̶and then you
do experiments and confirm thesepredictions.
A problem is that some people
have gone too far. They say that only
if all these processes are completed,say within the time scale of 10 or 20
years, then the theory can be called
science.
Murayama: Hopefully, within 10

years.
Nomura: I totally agree with the basic
attitude, but the question is that oftime scale. This is, for example, anorigin of the statement that string
theory is not science. I do not agree
that the definition of science includes
the condition that all these cycles
must be completed within a certain
time. Falsifiability we talk about
should not be like this. Whether
a theory is science or not should
be determined if it is in principle
falsifiable̶especially if the theory
has a reasonable chance to be true
̶though we should of course keep
trying to see if there are predictions
that can be tested in shorter timescales.
Gabriel: That indeed seems to be a
deep disagreement, and thatʼs very
interesting but itʼs a difference.
Nomura: Yeah, the difference is evenamong scientists.
Of course, if someone says that
I donʼt want to invest my time forsomething whose confirmation timescale could be 100 years, thatʼs fine.
Itʼs their decision, and I donʼt have any
objection. But I strongly disagree withthe statement that people working
on things that might take long time
to confirm are not scientists, thestatement that some people actually
make. The statement is, in fact,
dangerous because no one reallyknows future technical advancement
and also some other predictions may
be found which can be confirmed ata shorter time scale.
Murayama: As you know, I
sometimes made such a criticism
myself but that was not about string
theory itself but more about thepeople who were doing it because
they have the attitude that they donʼtneed to bother making predictions
or test them, and thatʼs the attitude I

13

Round
Table

was deadly against because then thatʼs
not a scientific attitude. Itʼs not thesame thing as calling string theory
not science but rather calling certain
attitude of people doing string theory
nonscientific. I made that distinction.
Nomura: Okay, good. Then I might
have misunderstood you at somepoint. But I would still say that eventhings people whom you criticize
are doing are not worthless efforts
as humanʼs activity̶it is, at least,
mathematics. In general, I believe
we must be extremely careful indismissing others or what others are
doing.
Murayama: Another thing about̶
I think what we are taught not insort of the textbook way but on theway we are doing research̶is about
the quality of theory, namely, that
we highly value theories, which are
more universally applicable, a broader
range of applicability.
We value theories that look more
beautiful and, of course, we canʼtreally define what we mean by
beautiful, but there is some aesthetic
sense of it, and we also value theories
that are useful, and in the case ofstring theory, it had not been verified
experimentally in a way we normallyspeak of but has been incredibly
useful in spawning new ideas andthat also created a new connection
to mathematics and so on.
So academically, there was a very
fruitful ground to conduct research.
Thatʼs another quality we value. So,
in addition to this narrow definitionof science we were taught, there arethese additional qualities. Somehow
we got sort of engrained why weactually keep doing research andwhat we aim for, and thatʼs a difficult
aspect we can define in terms ofwhat is science.
Nomura: Yeah, this may be

14complicated. At this point we are
not precisely defining science in sucha way that Markus can comment
precisely, but this may be the natureof the issue̶I mean, it may have a
lot of aspects like Hitoshi mentioned.
And some of these aspects aredifferent from what we were talking
about when we discussed falsifiability
etc. But anyway, listening to all thesethings what would you say?
What Science is–Philosopher sView
Gabriel: I think that you arehighlighting an important part ofthe scientific activity. So clearly,
there is a success criterion as well as
an overall legitimacy criterion. The
overall legitimacy criterion is what
you call falsifiability in principle ortestability in principle, right? Science
proceeds by making claims about
the universe that can be tested. If weassert something that is in principle,
or in virtue of the meaning of theterms employed in the statement,
beyond the reach of any instrument
we use for measurements, we simply
make no statement at all about theuniverse.
Nomura: God exists is a good
example.
Gabriel: There are other things too,such as life is a dream. The ideathat reality might not be at all what
it seems to us is also not a scientifichypothesis, as science minimallyrelies on the availability of data. If
data were not even data, we could
not proceed scientifically to establish
anything.
If I tell you that life is a dream,
there is of course a testable
hypothesis available too: how long isthe dream and so on. If I then replythat life might be something evencrazier, such as a nightmare in the

Kavli IPMU News No. 45 March 2019mind of an immaterial demon, thishypothesis would easily explain all
the data. However, there are infinitely
many other hypotheses which explain
all the data in one fell swoop.
Nomura: Yeah, and this is the theory
no one canGabriel: Itʼs a very simple theory. Itʼsextremely elegant. Itʼs very universal.
But there must be a little bit moreaction here because there are some
non-falsifiable things that are kosher.
For instance, if Iʼm conscious and I
think Iʼm conscious, then that is not
falsifiable. To be conscious and to
think that one is conscious meansthat one is right. Not everything thatis not falsifiable is problematic andunscientific. Otherwise, we could notformulate the criterion of falsifiability
itself.
So, I can be wrong about the statethat I am in. I can be wrong about
the neural support of consciousness,but not about the fact that I am
conscious right now. Being aware andbeing aware of being aware are thesame thing, so there is no falsifiability
gap, but that is alright. Therefore noteverything which exists is the objectof a falsifiable investigation.
Nomura: Okay, there may besomething more here.
Murayama: But when you talk to me,
if I respond, then you can tell I am
conscious.
Gabriel: Yes. Exactly! That can be
wrong.
Murayama: That is the external test.
Gabriel: Yes, thatʼs the external test.
There is an external test and itʼs also
very important that this fact about
consciousness, which I mentioned, isgrounded in the brain. If there wereno relations between consciousness
and the brain, we should conclude
that there is something wrong withthinking that we are consciousbecause then we would havesomething that is not falsifiable
and not grounded in anythingthat is falsifiable. Hence, there is adeeper relation between existence
and falsifiability, maybe even a very
deep one. So, thatʼs the in-principle
criterion. I think thatʼs kind of fine.
However, I will be careful as aphilosopher and letʼs see how thismaps onto science. Scientists are very
used to thinking of the in-principle
criterion and the success criterion.
The one is dynamic, the other one
is more static. There is the dynamicside of theory change, the activity ofadjusting to incoming data and thenchanging the model where necessary,and then there is a more generalcriterion, the demarcation problem
as we call it in philosophy of science:falsifiability as an answer to thequestion what makes an investigationa part of science.
Nomura: Such in-principle falsifiability
is, at least, necessary.
Gabriel: Yeah, necessary. Not
sufficient.
Nomura: to eliminate theories likeGod exists
Gabriel: Yeah, stuff like that.
Nomura: or like Fossils of dinosaurs
were made by UFO .
Gabriel: The demon stuff, yeah, stuff
like that, like demons.
Nomura: Yes, your demon is a good
example too.
Gabriel: There are infinitely manysuch examples.
Discussion about
Underdetermination
Nomura: Yeah. Using the falsifiability
criterion more than that, however, isdangerous, which some people aredoing and Iʼm against. I also want totalk about your underdetermination
which you mentioned in yourtalk. You, as a philosopher,thought about this, but I was also
thinking something like that, likeunderdetermination.
Gabriel: That is what we callunderdetermination
Nomura: For example, Hitoshi said
that I am conscious̶you must
know I am conscious, right? But I
donʼt know! Why? Because I donʼthave his consciousness. I donʼt reallyknow.
Murayama: But you have seen myfunction. I responded to your function…
Nomura: Oh, yeah, but that may
only be a function, right? I could saythat only I am conscious and what
I see as Hitoshi is just a function.
However, because similar responses
are obtained from Hitoshi as thosefrom myself, the simplest assumption
is that these two are both conscious.
In fact, this is exactly how science
goes. Namely, although I cannot
exclude the possibility that only I
am conscious and youʼre like, forexample, demons,
Gabriel: Or everyone is zombie...
Nomura: I cannot exclude such a
possibility, but I donʼt need to think
about it in doing science. Making
this kind of assumptions is a very
fundamental part of the definitionof science, which you probably agree.
Gabriel: No doubt. But hereʼssomething where I would introduce
maybe a more cautionary way of
speaking and then letʼs see what
you have to say about this because
we got into a discussion about. So, I
would stick to a picture where there
really are facts . Now, hereʼs why.
Murayama: So, the fact is the samething as truth ?
Gabriel: Yes. Let me define this a bit
more.
Nomura: Yes, what you talked about

in your talk – yeah.
Gabriel: I donʼt think of truth as
representational, so I donʼt think thattruth is a relation between a theory
and reality or a statement and a fact.
I think of a truth as just a fact.
Murayama: Okay, so thatʼs somethingthat exists.
Gabriel: Yes. Exactly!
Murayama: Whatever the definition.
Gabriel: Yes, exactly. Thatʼs how I
think about a truth. For instance,
when I say itʼs a truth that Iʼm here
and stuff like that, or itʼs a truth that
there are more than two people inthis room, with everything ( people ,room , in , etc.) well defined
Nomura: Yeah, you have to define
what the people and so on.
Gabriel: Sure. But hereʼs a view that,
I think, cannot be correct. A viewaccording to which once all the terms
are well defined, there is never a fact.
That canʼt be true, right? Because
once your terms are well defined,
either things are as presented or not.
So, imagine I tell you exactly what
I mean by an elementary particle,
which is hard enough but okay, thenthere is going to be an answer to thequestion whether in a well-delineatedspace-time region, there is an even or
odd number of certain molecules, say.
Letʼs take an even simpler question.
I mean thatʼs hard but Iʼll make it
simpler. Letʼs take a random arm of
the milky way, define a precise timeslot for it, and now there is either aneven or odd number of stars in thatpart of the milky way.
Nomura: After you define the star.
Gabriel: We assume that we fully
settled the meaning of star on thebasis of astrophysics.
Murayama: Which is hard to answer
but anyway.
Gabriel: Itʼs super hard.
Nomura: Practically. Weʼre not talking

15

Round
Table

about a practical issue
Gabriel: No. Some of those might be
impossible to answer, even when welldefined.
Nomura: Do you think so? This isindeed a big question. It is exactly
related to your theme, totality etc.,namely whether there is somethingthat is not answerable in principle.
Gabriel: Exactly. I have to think about
that. Maybe for no good reason, but
my bet is that there would be.
Take black holes, you had said very
interesting things about black holes
yesterday,＊2 anyhow some regionsof the universe, meaning the object
under investigation by physics, aresuch that it might indeed be thecase that there are properties inthat region that we can never figureout because, for instance black
holes, given that they suck all theinformation in and none comes out,
and if itʼs true, which is questionable
̶you made very interesting points
about that in your talk̶but if itʼs true
then physics cannot know anything
about the region of the universe
where no information comes out.
Then clearly there are physical facts
that physics cannot discover.
Quantum Mechanics andPhilosophy Seem to Have
Interesting Relation
Nomura: Then, such objects should
simply not be included, even in thelist of things to describe.
But the issue, in fact, is evendeeper. Here is the view I always
have had. An important problem
in quantum mechanics is that ofa measurement. Usually we think＊2

On June 10, 2018, Y.N. spoke on Beyond
the Universe and Gabriel on Universe,
World, and Reality at a public lecture hosted
by Kavli IPMU. There was also a dialogue
between the two lecturers; see Kavli IPMUNews No. 42, p. 19.

16

we can solve it by the concept of
information amplification in many
worlds̶by the way, this information
amplification has potentially very
interesting implications for whereconsciousness is, which we cantalk about later̶but to actually
implement it we always assume theexistence of an external object thatis observing the system. In classicalmechanics, this is not too much ofa problem because you can define
everything precisely, for example as akind of computer simulation, but inquantum mechanics the existence ofan external thing making some sortof observation is deeply ingrained in
its formulation.
So, quantum mechanics applies
to a subsystem̶everybody agrees
that it works perfectly then̶butwhat scientists really wanted is tofind a framework which includes
external observers, namely fullthings including such observers.
But your philosophy says that sucha framework might not exist. The
theory might be consistent without
it. I think this is quite possible. Maybe
physics can do in principle is only totalk about subsystems.
While I think it quite possible, usual
scientists donʼt think that way, whichis striking. Having said that, I would
say that the only way scientists canreach that conclusion, if we could
reach, is asymptotic. In fact, this isquite a general phenomenon. A
proof of a theory in naturalscience does not go like that inmathematics. You just have to keepincreasing your confidence about thetheory, in some sense by lowering theconfidence for alternatives.
Murayama: empirical science
Nomura: Yeah.
Gabriel: Thatʼs why it is empirical.
Nomura: Yes, thatʼs why the only way

Kavli IPMU News No. 45 March 2019

for scientists to reach this conclusion,or confirm Markusʼs view, is to try
to build a theory including external
observers and keep failing it. Thisis the only way science can reach
there.
Murayama: Thatʼs right. I agree withthat.
Gabriel: Yes. I agree with that too
and I think that this is why this modelthat I give, of the no-totality view,might be a very good descriptionof what science is doing because
science at most is reaching for totality
asymptotically, and it keeps failing inthat respect but in very specific ways.
Science as an epistemic virtue isthe degree of distance between an
impossible ideal and its capacity tonevertheless approach it, so scienceis, if you like, searching for thebiggest natural number. Well, there isno such thing. You will never find it,right? But nevertheless, as it does so,
it finds always more numbers. It adds
and adds, so itʼs a very successful
operation, even though it defines alimit that cannot be reached by thenature of that limit.
Nomura: This analogy is interesting.
But I want to be a little more careful
about my view. If the world wereclassical, then I think I might havetotally opposed to your thought.
Gabriel: Yeah, of course we can cometo it, right.
Nomura: So, it is very interesting thatquantum mechanics, which looks
like a very physics thing and is not atheory of philosophy per se, seems
important. Quantum mechanics isreally affecting how I think about
the nature. Because of quantum
mechanics, I feel that what Markus
says might be true, although I
certainly canʼt be conclusive.
Murayama: Can you elaborate onthat?

Nomura: Okay. Although I still thinkthat even a quantum world mightultimately be described internally,at least the issue is there. In the
Copenhagen way of thinking, forexample, to test a prediction you
have to make a measurement.
Usually you just say that sucha measurement is described bydecoherence.＊3 Suppose you havea quantum state which is an equalsuperposition of spin up and spin
down, and you interact with it. The
initial state is then the product of
you not knowing the spin statetimes the spin up plus down, andafter you interact with the spin, thestate becomes a superposition ofspin up and you think the spin is
up and spin down and you think
the spin is down. Then you may
write down the result on a piece of
paper, which further amplifies theup/down information, and so on. But
at which point did you really make ameasurement? To elucidate the issue,
suppose we have only two degrees
of freedom, a spin and me. Let us, forsimplicity, refer to my mental statefinding spin up as A and my mental
state finding down as B. Then you
could say that the state after theinteraction is̶this is nothing otherthan von Neumann measurement
̶equal to up A plus down B,
and you may think that you havemeasured spin up or down. This iswrong.
Murayama: Yeah, because it can still
be either way.
Nomura: No. Not in that sense.
Murayama: Oh, not in that sense?
Nomura: No, the conclusion is more
fundamentally wrong because you
can write down exactly the samestate as (up + down) times (A +B) plus (up – down) times (A – B)
, since the cross terms cancel. Then

you might say that the measurement
was done in the x direction, rather
than in the z direction.＊4 A standard
answer to this question of what
measurement you made is that it isdetermined through a succession
̶not just a single interaction̶ofprocesses: for example, I also write
down the result in a note, somebody
reads it, and so on. Namely, themeasured information is theinformation that is amplified in thesense that many people can share it.
Incidentally, you cannot sharethe entire information about asubsystem because of the no-cloning
theorem of quantum mechanics.＊5
Only an exponentially small amountof information can be shared bymultiple entities, and if this sharing
happens you say that the information
is classicalized. But at what point
does this really occur? Maybe you
always need some external entity,
or a sufficiently large amount of
amplification may be enough to claimthat things are classicalized. In thelatter case we donʼt need to go as
far as no-totality, but we donʼt reallyknow.

Where Is Consciousness?

Nomura: But it is still true that things
become classical only after someamplifications. And, since our thinking＊3

process in which quantum coherenceof a state ̶the origin of strange quantum
behaviors ̶ is lost from the system due to its
interactions with environment. This makes thesystem appear classical.

＊4

In quantum mechanics, a spin can takeonly two independent states, which one cantake to be "up" and "down." These are thestates which, when the z-component of theangular momentum is measured, give definite
answers: +1/2 and -1/2 in certain units. An
intriguing thing is that the states which givedefinite answers when the x-component ismeasurement are given by "superpositions"of these two states: (up plus down) and (upminus down), giving the x-component to be
1/2 and -1/2, respectively.

＊5

In quantum mechanics, full information
contained in a quantum state cannot be
copied faithfully. This results from the factthat any operation in quantum mechanics
acts linearly. Suppose there is a copy machinethat converts a spin up into two up's ̶which we write as (up)^2̶ and a down into
(down)^2. Now, imagine that we send asuperposition state (up + down) into this copy
machine. Since the action of the machinemust be linear, this produces the state (up^2+ down^2), which is not a copy of the originalstate, (up + down)^2, since the information
about interference terms is dropped. This
obstruction for duplicating information does
not occur in classical mechanics, which does
not have the concept of a superposition.

17

Round
Table

is probably classical̶we are nothaving a superposition thinking ̶
the question of where consciousness
is might be answered only after
such amplification, and in this sense
consciousness may involve somethingoutside a brain because the brain isinteracting with a lot of things. This iswhat I meant to say in passing earlier.
Gabriel: Iʼm very happy with whatyouʼre saying.
Nomura: Things become classicalonly after information amplification,
but how much amplification you
need? This may be a quantitative
question associated, for example, withhow stable the information needs
to become. But it is certainly truethat amplification occurs throughinteractions, so that your brain stateis copied to photons in some form,and so on. So, where the information,
namely consciousness, actually is?
Gabriel: What youʼre describing could
be a legitimate version of the ageold assumption that consciousness
has something to do with quantum
mechanics. But it might not be
consciousness; it might be thought.
The mental state I am in as a theorist
right now leads to classicalization.
It turns something into classicalamplification. So the operation thatyouʼre describing, which is obviously
related to the measurement problem
and so on, that operation could be
essentially tied to thought.
Murayama: Can you again define thedifference between consciousness
and thought?
Gabriel: Okay, so hereʼs what I mean.
Iʼll give you a notion of thought withwhich Iʼm working here. We can boththink the same thought. For instance,
Tokyo is a city. I tell you what I meanby city. I tell you what I mean by
Tokyo and so forth. We can thenthink the same thing, namely that

18

Tokyo is a city. Iʼll give you anotherthought. Tenno is the Japaneseword for emperor. So, thatʼs athought. Now if you agree and I
agree, is there something to which
we both agree?
I would say yes and philosopherscall̶in a certain tradition, which
I think is right; the mathematician,Gottlob Frege introduced thisnotion̶he called that to which weboth agree a thought and Fregedistinguishes between a thought andthinking. I can think that thought andyou can think the thought, and weboth think the same thought. So, thethought is not in my head. Otherwise,
we couldnʼt be thinking the same
thought. The thought is not in myhead, only the activity of thinking it
is.
Nomura: By the way, the concept
you are talking about applies only inclassical physics. This is because you
are assuming that information can be
duplicated. In quantum mechanics,
the full information cannot be copied.
There is a very simple reason for that̶the principle of linearity.＊5
Gabriel: Interesting.
Nomura: So, you cannot have anexact copy machine in quantum
mechanics. This is why our worldclassicalizes because a definition of
being classical is that we can sharethe information exactly andGabriel: Yes, exactly. Once we share
information, we are on the classicallevel. We have to be. Thought isclassical.
Nomura: Yes, a classical thing. But ourworld is quantum mechanical, deep
down. So, the notion you are talking
about must become something very
interesting at the fundamental level.
Perhaps even a concept like twoshare the same thought might not
be precisely defined at such level

Kavli IPMU News No. 45 March 2019because in quantum mechanics, tospecify the state of the world, youreally have to give a quantum state.
And the state is a global concept̶
you have to know everything about
the system in principle.
In this context, the relevant
question is why we can admit anapproximately classical treatment of
nature, not̶unlike sometimes posed̶why quantum mechanics admits
nonlocal phenomena, such as an EPR
pair.＊6 The nonlocal nature of a stateis intrinsic in quantum mechanics.
Nevertheless, you can predict what
happens if I just dropped this phonewhich I have in my hand without
knowing whatʼs happening in
Andromeda, despite the fact thatthe quantum state must include
everything in the world
So, your information and myinformation, those are shared̶
minute you say something likethose, you are already separating
your quantum state into pieces andentering into a classical regime. So,
how does such classicality emerge?
I donʼt know whether this is aphilosophical question, but it is very
interesting.
Riddle of the Unity of the
Proposition
Gabriel: I think it is a very
philosophical question that is
amenable to a scientific treatment. It
is, in a certain sense, the philosophicalquestion because itʼs a question of
how thought emerges in a nonthinking environment. Only parts of＊6

In quantum mechanics, one can consider
a quantum state in which two objects, e.g.,spins, are correlated in such a way that thestate of each object cannot be describedindependently of that of the other. Thisphenomenon is called entanglement, and theEPR (Einstein-Podolsky-Rosen) pair is a specificform of entanglement between two objects.

the universe think.
What if we have a picture where
reality, indeed, is what we arethinking about, so the thought hasa physical trace, a signature in theuniverse? If we can assign a physicallykosher signature to a thought, thenwe cross the gap between thinking
and reality because now we canunderstand how what we are doing
when we are thinking is graspinga thought because we know much
more about what we do when weare thinking in the brain and whatmust happen on the object side
when reality stabilizes or classicalizes
into a thought.
This might be related to a reallyfamous riddle. It is called the Riddleof the Unity of the Proposition.＊7 This
is not solved. A student of mine justwrote a brilliant thesis about it, but
it does not amount to a complete
solution. Itʼs brilliant but it doesnʼtwork. The other reviewer said
we could still give him Ph.D. as hethought the issue through̶thatʼswhat we do in philosophy̶and heindeed got the best grade because
the solution was brilliant. But it canʼtbe the whole story.
Here is the problem of the Unity of
the Proposition. There must indeed
be an answer that physics can give.
Bertrand Russell kind of discovered
this problem, but it is in fact older̶it
had already been discussed in Plato.
Imagine that I think a certain thoughtsuch as that the dog is on the mat. If
I think that the dog is on the mat̶or
letʼs take something that is actually＊7

The unity of the proposition is the problem
of explaining how a sentence expresses
more than just what a list of proper names
expresses and how a sentence comes to betrue or false? For example, if Socrates is
wise consists of just a name for Socrates, anda name for the universal concept of Wisdom,
how could the sentence be true or false?

there in this room, so the bottle ison the table. Alright? Now, on mydefinition of thought, that the bottle
is on the table is the thought that thebottle is on the table.
Murayama: Say that again.
Nomura: Yeah, right. To understand it
betterGabriel: On my definition of thought,
okay, here is what the thought is. The
bottle on the table̶the thought thatthe bottle is on the table is not in mymind. It is here. What you perceive
is both a bottle on the table, andthe thought that the bottle is on thetable. There are not two things inreality, but an inseparable unity of
information and object.
Murayama: Okay.
Gabriel: So, there is something in mymind right now. I see the bottle fromhere. You see it from there, but weboth see the same thing, the bottleon the table. Hitoshi, you see it fromthere, I see it from here, and Yasunori,
you see it from there, but there is
one fact: the bottle on the table.
Thatʼs why it is fair to say that once I
define all of my terms precisely
Nomura: You have become ascientist!
Gabriel: Philosophers are scientists
too, you know
Nomura: Itʼs a bit nasty to talk about
making everything precise every time,but
Gabriel: Not nasty, defining things
is very important. Anyway, imagine
we completely define our concepts at
the highest level̶namely giving you
the highest, the most fine-grained
scientific account of what I mean
Nomura: Okay. That is not the point
here anyway.
Gabriel: You know, we really fix themeaning of bottle, table, etc.
Nomura: Okay.
Gabriel: Now we have the thought

the bottle is on the table. You process
the thought in the way in which yourorganism does it for you and I do it
for me and letʼs call that thinking. So,
the activity of processing a thoughtis thinking. What I am thinking is
the thought, but what I am thinking
when I am thinking that thought isreally the bottle on the table.
Murayama: So, youʼre saying that thisobject is the thought.
Gabriel: Indeed.
Murayama: Okay.
Gabriel: This is what philosophers calla fact.
Nomura: Okay, but I didnʼt get whatis the puzzle
Gabriel: I said something which I
hope is true, right? So, it doesnʼt yet
come with a puzzle. But here is aproblem now. Can thoughts be false?
Can there be negative facts?
Murayama: Can thoughts be false?
Gabriel: Yes; Can there be negative
facts? So, imagine there are no
negative facts. Here is a positive fact
̶the bottle is on the table. Now, isthere a negative fact here too, forinstance, the fact that there is no pig
on the table?
Nomura: Negative fact means that
there is no pig on the table?
Murayama: Itʼs a fact.
Nomura: Yeah, that is a fact.
Gabriel: Yeah, but is the fact
negative? The fact that there is atable entails that there is no pig
exactly where the table is. Is reality
composed of positive and negative
facts?
Nomura: It seems that there is onlya fact that molecules, or particles orwhatever, are configured in a certain
way
Gabriel: For sure, molecules are
involved in facts, and those facts are
not negative. But now the problem isthis. Suppose no fact is ever negative,

19

Round
Table

and there are just more positive facts.
Then, imagine that I change the facts.
Currently, the facts are such that
there is a bottle. Now, I change them.
By this, I didnʼt create a negativefact. There is just a new fact, not anegative fact.
Murayama: Yeah. That is a new fact.
Nomura: Of course, you could define
it as a negative fact, but that would
just be a convention
Gabriel: The question is: If there are
no negative facts, then how can I
make a mistake in thinking? Imagine
I think something. I think a thought.
I process reality. How can I makea mistake if there are no negative
facts? Then, reality would be coming
in all the time and thatʼs it. Facts will
be coming in. How do we explain
the subjectivity, i.e. fallibility, of ourrelationship with reality?
Nomura: I would say the following.
For example, despite the fact thatthe bottle is here̶in the sense that
Hitoshi has a thought that the bottle
is here on the table and you also
share the thought that the bottle ison the table, and everybody shares
the same thought̶despite that, if I
am having a thought that there is nobottle, then that can be taken as adefinition of mistake.
Gabriel: Yes, that would be a mistake.
But now that mistake is a relation
between something thatʼs going on
in you and something thatʼs here on
the table, right? And now you see
if thatʼs your theory, you see you
have the correspondence theory of
truth. Because now youʼre saying thatyou have a theory of mistakes, andyou make a mistake if whatʼs here
doesnʼt correspond to whatʼs there.
And correspondingly, now you candefine what happens when you donʼtmake a mistake. If you donʼt makea mistake, then whatʼs here (in my20mind) corresponds to whatʼs there on
the table. That is the correspondence
theory of truth. Now, you have it.
How Truth/Falsity Is Defined in a
Quantum Mechanical World?
Nomura: Yeah. I am saying something
like that, but not quite. A mistake inmy theory is defined only statistically.
At least in a quantum mechanicalworld, you always have to think
about things in terms of a confidence
level or something like that. Supposethat̶I also gave you this example
earlier＊8 ̶suppose that the massof a particle called the Z Boson is,
letʼs say for simplicity, 90 GeV. That
corresponds to the existence of apeak at 90 GeV in some spectrum
̶with the existence of such a peak,
we usually say that the mass of theparticle is 90 GeV. But, maybe thetrue value is 80 GeV. Since inquantum mechanics everything isstatistical, a rare coincidence may
have happened that the result of anexperiment is pretending that themass is 90 despite the fact that thetrue value is 80. You might still saythat it canʼt be the case because
other experiments also found
90. But the result of this otherexperiment may also be a statisticalfluke. If you think in this way, you
canʼt do anything.
So, when we do science, we arealways using, at least implicitly,
the concept of typicality, and we
temporarily view a thing as a truth
if it is highly confident in this sense.
So, if we had 100 people seeing thebottle here on the table and I am
the only person who does not see
or measure it, then it would give ahigher confidence that I am making
a mistake. And if you have thousandpeople seeing it and I am still saying
itʼs not there, then it becomes more

Kavli IPMU News No. 45 March 2019confident that I am making a mistake
Gabriel: Yeah, but hereʼs the problem.
Murayama: Yeah, then you can neversay you made a mistake.
Gabriel: Yes, you can never say thatyou either made a mistake or thatyou got it right.
Nomura: But I think this logic is stilltrue nevertheless because
Murayama: What do you think istrue then?
Gabriel: Now, Yasunori, what you
said seems to imply that there is no
falsifiability either. Because if there
is no absolute truth, then there is
no absolute falsity. You can also not
falsify a theory.
Nomura: I agree.
Gabriel: Agree?
Nomura: Yes, I agree.
Gabriel: then you can stop using atheoryNomura: I mean, Iʼm saying thatfalsifiability must also be a statisticalstatement exactly as the statement I
am making a mistake in the previous
example is a statistical statement.
Likewise, the mass of the Z Boson is
90 GeV is also a statistical statement,
at least in a quantum mechanicalworld, and practically even in aclassical world, I think.
Murayama: That is the standard wayof approaching quantum
Nomura: Yes, I think so.
Gabriel: Thatʼs true.
Nomura: Indeed, things are always
like that. Any criterion, such as trueor false, is in fact almost always
continuously connected, and soyou must cut somewhere. And yourexample̶a bottle on the table̶is
not an exception. This is important.
＊8

After M.G.ʼs seminar, there was a panel
discussion by three panelists including M.G.
and Y.N., where the example discussed here
was talked about prior to this round tablediscussion.

I claim we must always think in thisway at the fundamental level.
Gabriel: Always, and there is no fixed
number.
Nomura: Yes, exactly.
Gabriel: You work as you go andthen all these contextual parameters
are coming in.
Nomura: Exactly!
Gabriel: You work as you go. You
cannot give a calculus for it. If there
is no absolute certainty, there is no
falsifiability either!
Nomura: Iʼm very sympathetic to that.
Murayama: Yes, that contextual partis really true in a sociological sense
in physics community. If you claim tohave discovered new particle, like the
Higgs Boson, the stake is so high thatit requires 99.9997%.
Gabriel: Exactly! You raise the stake.
Murayama: But when you say thatsomebody is handing you a theory,
there should be a new particle,
nobody really cares. You takethe data. You have excluded the
hypothesis. Then, even at the levelof 90% confidence level, you would
take that as a fact̶ Okay it didnʼtexist.
Nomura: Yes, thatʼs sociological but
interesting
Murayama: Yeah, thatʼs the definition
you mentioned.
Gabriel: You see, this shows, in acertain sense, that the falsifiability
criterion also fails.
Nomura: In the exact sense.
Gabriel: Yeah, in the exact sense.
Murayama: Because itʼs not 100%.
Nomura: Yeah. I think the case of adolphin is also the same̶I mean, if
we trace the motion of all the atoms
by, e.g., a very strong computer,then we donʼt necessarily have to
introduce the concept of dolphin,human, or anything like that, since
we just have to follow the motionof all elementary particles, whichcontains all the information. Almost
all the concepts we are talking
about are implicitly and intrinsicallyapproximate, like artificially dividing
a continuous thing, and this divisionmust even be statistical, at least ina quantum world. In fact, we mighteven be able to turn the argument
around and say that this is the reason
why the fundamental law of physics
takes the form which quantum
mechanics does
Gabriel: So, whatʼs really going on is acertain̶if you like, within thinking̶fluctuation, a probability fluctuation
at the level of thinking too, right?
There are certain points of the wave
and they are relative to contextual
parameters themselves and then wesay, okay, we call this falsification,and this confirming evidence, and thisdata. But you see this is very different
from Popperʼs picture of falsification
because the falsification picture is
one which worked like the following:
all ravens are black and then you finda white one and itʼs like, damn, I waswrong. So, you take this back.
That was the model, where reallythe falsification picture presupposesthat there are facts and either you
get them or you donʼt, and Popper
just said that you never get all
the facts. You always get a partial
glimpse and the more facts comein, maybe some disconfirming facts
come in too and thatʼs it. So, Popper
would say that science goes like this.
All ravens are black. False, there is awhite raven, and then itʼs like damn,
forget about the black ravens. What
do I know about ravens? Thatʼs theconclusion. Then, Iʼm not interested inravens anymore.
Murayama: Thatʼs a really saddefinition of science.
Gabriel: Yeah. Thatʼs not what it is,right? So, there has to be middle
ground level, where the dynamics
simply canʼt stop. Right? But this is
not driven by inductive data sampling.
Nomura: As I emphasized, always
you are using statistical inference toreduce the number of assumptions,
namely getting a better theory.
For example, suppose your theory
predicts that all ravens are black, but
you observe a white one. Then you
usually say that you falsify the theory,and thatʼs okay. But in principle, you
cannot exclude the possibility thatyou instantly became achromatopsia,
so that you couldnʼt process thecolor correctly, and then got backto normal. You cannot exclude thisexactly, so we are implicitly assumingthat such a thing occurs only with anextremely small probability, implyingthat your theory is excluded at a very,
very high confidence. Like this, we arealways using statistics.
Gabriel: Some version of so-called
holism is probably correct here. Quine
proposed to think of physical theory
as a web of beliefs whose end points
are measurements. We are in touchwith the universe, but we extend ourbelief system with the help of physics.
Science is not just a collection of
sensory data and inductive claims.
Murayama: Does it need to be reallyhuman sensory system or it can beextended by instruments?
Gabriel: Yes, it can be extended
by instruments and thus bymeasurements.
Murayama: Okay. Thatʼs good.
Nomura: This is precisely why theissue is interesting. In a classicalworld, the probabilistic nature inthese processes is usually attributed
to incomplete knowledge, namely
you donʼt know enough with
precision.
Murayama: Like a weather forecast.

21

Round
Table

Nomura: Yeah. But if you know
perfectly the location and velocityof all the elementary particles andhave a hyper-strong computer, thenwe donʼt need to introduce such aprobabilistic nature
Gabriel: Yeah, then it will be fine.
Discussing Consciousness Again
Nomura: But quantum mechanics
says that this is not the case.
Probability seems to be much more
fundamental. But then this brings us
to the issue of consciousness. You
could say Oh wait, you say thatprobabilities are the only thing thatcan physically exist, but I exist in a
specific place in specific time. This
may require something like goingback to consciousness̶do I haveto introduce consciousness in thedefinition of physical law? I doubt,
but I donʼt have a definite conclusion.
Gabriel: But here is how you could
maybe map decoherence＊3 ontothat picture, so not do it withconsciousness but do it with thought.
So, what if a measurement̶in thesense of the measurement problem̶
takes place once I stabilize a thought
environment, so itʼs not internal.
Consciousness is typically seen as
something very private, intimate,right? I canʼt see your consciousness.
Thatʼs typically implicit in the concept
of consciousness.
But if we have this other conceptof thinking, then maybe that could
do it, where thinking is putting me asa measurement system̶the wholeanimal that I am̶putting me intouch with my environment and myenvironment now, the environmentof an animal, is going to be classical.
Otherwise, the animal couldnʼtsurvive. The animal doesnʼt jump overprobabilities. Thatʼs why Schrödingerʼs

22

cat is so aptly chosen. Itʼs an animal.
Thatʼs why we are like okay, is it
dead or alive? So for that it mattersfor animals to be dead or alive, somaybe we are the kinds of systems
that as thinkers
Nomura: Iʼm sympathetic. In fact,
in one of the papers＊9 I evensaid something like that. The
classicalization relevant here may
just be information amplification̶
thatʼs the possibility I discussed. Iʼm
not pushing consciousness is very
important and necessary.
Gabriel: No. Itʼs not consciousness.
We are not talking about
consciousness.
Nomura: Maybe yes, but Iʼm not a
proponent of that.
Gabriel: But thatʼs really not the
proposal here. Itʼs really a much moreobjective proposal, nothing having to
do with subjective consciousness .
Murayama: So how does thinking
and thought work, to address thisquestion?
Gabriel: Okay. So here is the picture.
A thought can be true or false.
Determinately it has two states, A or
B, on/off. Thatʼs why you can translatethoughts into information.
Murayama: Okay. So, that is classical.
Gabriel: Thatʼs classical. I think
thought is classical.
Liar Paradox
Nomura: Yeah, but because you arereferring to A or B - or Yes or No-type statement often, I would raise
this. What do you think about I am aliar -type situation?＊10
Gabriel: Oh, yeah. So, well, I thinkthat can be solved because the liar
paradox is the following proposition.
L: L is false. So, this is how you
formalize it. Itʼs simple. Now, aninteresting solution̶there are many

Kavli IPMU News No. 45 March 2019solutions to it̶but here is the one
I really like. A recent one by a friendof mine, Sebastian Rödl, a German
philosopher, he says the liar paradox
is just nonsense. There is no paradox.
Here is how.
So, imagine I look at you and I justutter the words I told you, and now
you ask me What? What did you tellme? Out of the blue, itʼs like I told
you and you look at me what?
and itʼs like well just that. I told
you! Now, what did you tell me? isa good question, right? So, Iʼm notsaying anything if I just claim I told
you. I canʼt tell you it without saying
what it is. So, the liar paradox justdoesnʼt specify truth conditions. It
contains a statement apparently
saying about itself that it is false
without specifying what it is.
Nomura: Yeah, that is interesting. But,
is this something you have to solve ?
I thought that when Gödel proposed
it, he meant to show that there isan intrinsic limitation in Boolean
yes or no logic, and not presented
as a paradox. This is just a featureof Boolean logic, that it cannot becomplete.
Gabriel: Yeah. Thatʼs one way of
dealing with it or you can say accept,
for instance, dialetheism, which is aninteresting logical view. According
to this view, you can say that the liar
sentence is both true and false.
Murayama: Both true and false?
Nomura: Yeah. You are just sayingthat Boolean is not enough̶you＊9Y. Nomura, Quantum mechanics,
spacetime locality, and gravity, Found. Phys.
43 (2013) 978, arXiv:1110.4630 [hep-th].

＊10

I am a liar : if he is correct (TRUE), then heis a liar (FALSE); if what he is saying is wrong(FALSE) then he is not a liar (TRUE). (Perhaps, abetter sentence was This sentence isfalse. ) Y.N. raised this as a possible example
for something that cannot be answered
simply by Yes or No.

have to extend it.
Gabriel: Exactly, that can be done.
Murayama: Thatʼs along the sameline of thinking then.
Gabriel: Yes. That can be done. Thatʼs
one form of paraconsistent logic.
Nomura: Okay.
Gabriel: So, no problem. But mysolution is even easier. I think thatwhen I say I am lying and I am
not telling you anything, then I am
not lying. So, thatʼs why there is noparadox. You need to say somethingin order to create a paradox.
Murayama: But if you say I always
lie , then it is a paradox.
Gabriel: Now, yeah. Now, it becomesa paradox. Yeah. I always lie. But, thenI would say the answer to this is no. If
someone tells me I always lie thenI could say no because what youʼvejust said is neither true nor false, so
you donʼt always lie.
Thatʼs why we typically formulate
it like this. We abstract from the
speakers because otherwise you canjust deny that this is a legitimate
speech act. You can just say donʼt
speak this way, right? So, if we
formalize it, usually we say something
like proposition L, so we call thesentence L and the sentence L says L
is false, right? So, now itʼs true.
Nomura: Exactly, so negative
feedback is always outside the
Boolean logic.
Gabriel: Indeed. So, we know that
this indeed causes problems, and I
think that this is part of why I think
there is no totality, even in logicalspace because if there were totality
in logical space, the liar would be inthere too. So, you have to rule out
something, for instance the liar. You
have to be justified in ruling out theliar paradox and other paradoxes inorder to have a theory at all.
Nomura: Interesting. I believe thisis related with quantum mechanics,
why quantum mechanics isformulated in a way that it applies
only to subsystems. Iʼve always feltthat this may be related with
Gödelʼs.＊11
Gabriel: Yes, I think so too.
Murayama: Okay, Yasunori. Thatʼs
why you brought this up.
Nomura: Yes. I always thought thisway.
Gabriel: My theory on thefundamental level is a kind ofgeneralization of what we know
from Gödelʼs theorems and theirconsequences. There are still
problems in Gödel. For instance, if
you assign a Gödel number to asentence without accounting for thefact that the sentence has meaning,
you did not really do the trick. Gödel
needs a theory of semantic meaning
before he can prove what he wanted
to prove. Gödel doesn t give you atheory of meaning. He gives you aformal system, which prints out astring of symbols. If no one is aroundto understand them, no proof everoccurred.

Now, if my arguments are sound,they provide us with a generalized
Gödel scenario. I worked out
a generalized incompletenesstheorem, so wherever you shootfor completeness, you canʼt get it.
Thatʼs my argument. Itʼs very strong
and general̶so it has to apply toquantum mechanics too.
Nomura: Yes, thatʼs what I am saying.
Gabriel: Yes. Absolutely!
Nomura: Wow, it seems we have only
10 minutes. We had a lot fun, but
how to assemble all these in the formof an article? Isnʼt it too difficult?
Through an Encounter with
Philosophy Science Knows What
It Is
Gabriel: Yeah, we can wrap it up. You
see, for instance if we tackle this very
specific issue, which came out now
at the end, I mean I clearly formulate
with my theory something that is＊11

A set of two theorems formulated bymathematician Kurt Gödel. They state thatevery formal axiomatic system capable ofmodelling basic arithmetic is incomplete, i.e.,
has some intrinsic limitations.

23

Round
Table

in principle falsifiable, in principle
testable, then it has consequences for
our way of doing and understanding
quantum mechanics clearly, because
now you have to choose and so
you could falsify what I am saying.
Itʼs a high-stakes claim. If you canshow that quantum mechanics is acomplete system, then you would
have falsified what I am saying.
Nomura: At least, in a quantum
mechanical world.
Gabriel: Yeah, at least. That issomething general.
Nomura: Because mathematicallyGödel is an example of yourGabriel: Yes, mathematically Iʼm rightanyhow.
Nomura: Yeah, because philosophy ismore general
Gabriel: So, Iʼm right anyhow.
(Everyone laughed.) But I havean additional stronger claim. The
hypothesis is that the general view,the generalized stable view, mygeneralized Gödel thing, must haveconsequences within quantum
mechanics too, something I see inwork by Carlo Rovelli too with whom
I once discussed this in a public eventin Marseille.
Nomura: A narrow version of yourphilosophy seems like the claim thatyour principle also applies to thephysical world.
Gabriel: Yes, thatʼs the narrow
hypothesis.
Nomura: I think this is at least areasonable chance to be true.
Gabriel: Yeah. Yes. That would beremarkable, right? That, I think thishas real consequences for physics,
right?
Nomura: I think so. What we aresearching for, i.e., a complete logicalframework of whole Nature, may besomething that does not exist, but
again the only way to scientifically24know it is to keep trying and failing.
So, in that sense, what we will bedoing must be the same anyway,
but it is always good to have in mind
the other possibility offered by a big
philosophical thinking, which saysthat failure may not necessarily meanthat we are weak but may indicate
something fundamental̶such acomplete framework simply does notexist. This is literally where philosophy
and science meet, and itʼs fun.
Gabriel: Yeah, this is a really funquestion. I think we have now
achieved an understanding of someof the things I say as a philosopher
and things that actually show up inphysics that we can continue fully
articulating. But if we articulate that,
I think this is a philosophy of sciencethat I have never seen. I doubt thatthe scientific hypothesis that we haveformulated and with ramifications
and consequences for understandingof science, knowledge, and reality
̶I doubt that anyone has everformulated it.
Murayama: So, philosophy of sciencecan be tested experimentally.
Gabriel: Yes. Thatʼs the claim. Sciencecan know what science is if it talks tophilosophers. Philosophy of science as
it is currently practiced in my view isa failure. We need to cooperate andbring actual metaphysics (or rather
what I call ontology) and physics
together.
Murayama: Thatʼs really amazing.
Yeah.
Gabriel: So, science itself becomes
reflective and thereby we falsify
Heideggerʼs famous claim thatscience doesnʼt think. Science itself is
a form of philosophy.
Nomura: Yes, I strongly support thatidea.
Gabriel: Yeah.
Nomura: Like one branch of

Kavli IPMU News No. 45 March 2019

philosophy.
Gabriel: Itʼs a branch of philosophy.
Murayama: I think every scientist
would agree with that.
Nomura: Yeah. But itʼs not completely
well articulated because itʼs slightly
person dependent, I mean at a
detailed level. The basic themeis probably shared by almost allscientists, but itʼs very interesting toeven study this.
Gabriel: Yes, there is no research
project on this, right? I mean
Murayama: One thing Iʼm sure you
know that some scientists use theword philosophy in a somewhat
derogatory fashion.
Gabriel: I know. Yeah.
Murayama: In a negative way.
Gabriel: Stephen Hawking and soon, philosophy is dead and so on. But
then they donʼt define philosophy. So,
Stephen Hawkingʼs claim philosophy
is dead is maximally unscientific,
right?
Nomura: Because he didnʼt define
Gabriel: Philosophy or science forthat matter.
Murayama: Excluding something hedidnʼt define. Thatʼs great.
Gabriel: Yeah. Great! Saying thatphilosophy is dead is like, well, I donʼtknow what they mean but if theymean that Jesus is dead with theword philosophy, then itʼs true, hedied, if he ever lived. But if they reallymean philosophy is dead, then they
are saying physics is dead too.
Nomura: Yep, because physics is
a form of philosophy. Thatʼs what
weʼre talking about. Everything isphilosophy!
Gabriel: Yes. Absolutely! So, thisremarkable feedback loop, you
know... So, science can look upon
science within science.
Murayama: Thatʼs great. Yeah.

Toward Changing Misconceptionof Science by General Public
Gabriel: You know this as a scientist,
but that has never been built into aphilosophy of science. All philosophyof science that I know of is dualistic.
They think of science there,
philosophy there. So, the scientists
do their stuff. They are basicallysuper smart engineers, right? Theybuild machines and figure out things,
right?
Nomura: And calculate.
Murayama: Thatʼs the perception.
Gabriel: Yeah, thatʼs the perception
but thatʼs a terrible perception. Thatʼsa terrible misunderstanding.
Murayama: Right, exactly! I strongly
oppose that.
Nomura: Yeah. Thatʼs not what
science is.
Gabriel: No, no way.
Nomura: But on the other hand,
many scientists seem to be justdoing that, so thatʼs why this kindof interaction is interesting andpotentially useful because science is
not just engineering or calculations.
Gabriel: No, even though you need to
do that. You might behave like that
but that doesnʼt mean that what you
are doing is that. If we achieve thislevel of self-reflection, then a lot of
public perceptions of both philosophy
and science would totally change.
And given that modernity̶modern
democracy and so on̶is logicallydrawing on technology and sciencebut with a bad understanding ofwhat that is, what we are doing now
has much bigger consequences thanmerely answering a certain problem.
If you articulate this in the right way
Think of the social consequences if
we brought actual science and actual
theoretical philosophy together!
Murayama: Thatʼs really important
too because there was actually

new study of truth waves I haveseen, which talks about how public
perceives science. By and large,
people tend to trust science. Thatʼs
the sort of what comes up in thesurvey, but they clearly state thatthey feel decoupled from science
because they donʼt know what
scientists are actually doing and how
they are thinking and so on and soforth. They arenʼt quite sure whether
they can really trust the stuff. So, that
disconnect is actually causing social
problems.
Gabriel: Yes. A real social problem,
which in turn becomes a scientificproblem when we figure out what
the social problem is, so we get thisloop back into the picture.
Nomura: Two comments. At the very
least, what we have demonstrated
today and yesterday is that at leastin Japan, there is a public demand.
Look at todayʼs event! This was donein a room on the 13th floor of somerandom building, and yet the room
was packed. In our dialogue
yesterday＊2 as well, there was large
audience. So, the demand is there.
Gabriel: Yeah. No doubt.
Nomura: The second is that̶thisis seconding Hitoshi s comment̶people may not really know what
scientists are doing and how theywork. For example, in todayʼs event,someone asked the role of intuitionin science, right?
Gabriel: Yeah. Yeah.
Nomura: I said that in doing science
we certainly use intuition, but the
final outcome, whatever a physicallaw or alike, should not rely on
intuition. And he was like Wow!
That makes things clear! I thought
I just said an obvious thing, but thatwas eye-opening to someone. So,
maybe even intellectual people, likethose coming to our events andasking good questions, may not reallyknow what we are doing and underwhat philosophy. So, discussion likethis in public settings would be very
helpful.
Murayama: Thatʼs absolutely clear.
Gabriel: I think the demand is verylarge. I mean the fact that̶and itʼscoming from different directions̶...
So, I became aware of the power ofthat demand by being contacted byscientists
Murayama: Uh-huh.
Gabriel: Yeah, Hitoshi, like you, which
confirms exactly. I was invited here,
right? So, my activity and your activity
overlapped, so that at some point I
had an e-mail in my e-mail box. And
the fact that I got these invitations
means that within the system ofscience itself, that arises, right?
This must have something to dowith the state of the art in science, so
science itself is even becoming morereflective, and as it does, it changes
its nature. So, there is something very
progressive going on right now, andthen given that the social system ofscience is deeply interconnected withmodern technology, and therefore
democracy and so on, there is thisadditional feedback loop. So, there
are a lot going on, and in Germany
there is clearly that demand too.
Nomura: Oh, I also had the thirdcomment. I enjoyed todayʼs dialogue
a lot!
Gabriel: Thatʼs likely the most certain
thing.
Nomura: Yeah. This is really true,
confidence level 99.99
Gabriel: Me too. Yeah. This was
great!
Murayama: It has always been aquestion to myself what exactly Iʼmdoing? because the scientificmethods have been sort of taught
and enforced on me̶it didnʼt come

25

Round
Table

out of me. Because I m practicing
myself, and itʼs my life, why Iʼm doing
this and why that is important andwhat does it mean. I think thosequestions would keep coming up.
And this dialogue was very helpful
̶it didnʼt answer those questions, I
have to say, but weʼve been thinking
about it.
Nomura: Yes, thatʼs what we can bethinking about. Philosophy is about
thinking!

Kavli IPMU Seminars→ continued from page 35

48. Holographic RG flows from 7Dgauged Supergravity
Speaker: Alessandra Gnecchi(CERN)
Date: Mar 07, 201949. Coulomb branches ofsymmetrizable quiver gauge
theories
Speaker: Hiraku Nakajima (Kavli
IPMU)
Date: Mar 07, 201950. Emergent inflation from a
Nambu–Jona-Lasinio mechanism
in gravity with non-dynamical
torsionSpeaker: Antonino Marciano(Fudan U)
Date: Mar 11, 2019
51. Integrable coupled sigma-models
Speaker: Benoit Vicedo (U York)
Date: Mar 12, 201952. Higgs signatures in primordial
non-Gaussianities
Speaker: Yi-Peng Wu (RESCEU,U Tokyo)Date: Mar 13, 2019
53. What are derived manifolds?
Speaker: David Carchedi (George
Mason U)
Date: Mar 14, 201954. The Inconsistent Universe:

26

Gabriel: Yeah, philosophy doesnʼtanswer anything! (laugh)
Nomura: Not necessarily, thoughsometimes it does
Gabriel: Within the division oflabor, my role, I think, as a generalphilosopher is to look at different
pockets of scientific knowledge andthen all these feedback loops arestarting. And now we are ready inthis whole fluctuating network, andwe know if we change something

here, then given that itʼs a field̶thatʼs
why I have the field metaphor in myphilosophy, field of sense̶so if you
do something in this field, probably
there are entanglement phenomena
across fields of sense.
Murayama: Okay.
Nomura: Great! Nice meeting you.
Gabriel: Good. Weʼll continue.
Murayama: Thank you so much,
Markus.
Gabriel: Thank you very much.

Problems with KiDS, or with
LambaCDM?
Speaker: Benjamin Joachimi (UCL)
Date: Mar 19, 201955. The holographic dual of theOmega-backgroundSpeaker: Kiril Hristov (Inst for
Nuclear Energy and Nuclear
Research (INRNE) at Bulgarian
Academy of Sciences)
Date: Mar 19, 201956. Cosmology with weakgravitational lensing: challenges
and opportunities
Speaker: Elisa Chisari (U Oxford)
Date: Mar 19, 201957. The Higgs Trilinear Coupling and
the Scale of New Physics
Speaker: Spencer Chang (U Oregon/ National Taiwan U)
Date: Mar 20, 201958. Black hole information and ReehSchlieder theorem
Speaker: Kazuya Yonekura(Tohoku U)
Date: Mar 20, 201959. How Dark is the Universe?
Intensity Mapping in Broadband
and Beyond
Speaker: Yi-Kuan Chiang (Johns
Hopkins U)
Date: Mar 22, 201960. Maximally supersymmetricbackgrounds and partial N=2 →N=1 rigid supersymmetry breaking
Speaker: Sergei Kuzenko(U Western Australia)
Date: Mar 25, 2019
61. Nilpotent Goldstino superfields
in supergravity and cosmologicalconstant
Speaker: Sergei Kuzenko(U Western Australia)
Date: Mar 26, 2019
62. The potential of generalized
Kahler geometry
Speaker: Marco Gualitieri(U Toronto)
Date: Mar 26, 2019
63. Are the small parameters in thequark sector related?
Speaker: Dipankar Das (Lund U)
Date: Mar 27, 2019
64. Alternative Fayet-Iliopoulos terms
in supergravity
Speaker: Sergei Kuzenko(U Western Australia)
Date: Mar 27, 201965. Elliptic Artin groups I
Speaker: Kyoji Saito (IPMU)
Date: Mar 30, 201966. Elliptic Artin groups II
Speaker: Yoshihisa Saito (Rikkyo U),
Hiroki Aoki (Tokyo U of Science)
Date: Mar 31, 2019

Kavli IPMU News No. 45 March 2019