The
Journal of Philosophy, Science & Law
Volume
10, August 11, 2010
www.miami.edu/ethics/jpsl
Knowledge and Mystery: The Impact of
Contemporary Science on
Metaphysics
Pierre Darriulat*
* Professor of Astrophysics at the Hanoi University of Sciences, Vietnam
Abstract
The article, meant
to address philosophers and scientists as well as the interested layman, expresses
the views of a physicist on the strong impact that contemporary science has on the
traditional approach to metaphysics, implying an in-depth revision of many
concepts that have been happily used for centuries. The implications of taking
seriously the main message of contemporary neurosciences – there is nothing
else than interacting atoms in our brains – are explored. Free will, and its reconciliation
with scientific determinism, is used as an illustration. Contemporary science
has shed new light on the circularity of knowledge and allows for a clearer separation
between science and metaphysics, between knowledge and religious beliefs. At
the same time it reveals the fundamental inability of knowledge at unravelling
mysteries such as knowing why the world exists, rather than nothing.
Introduction
We all wonder
about questions of a metaphysical nature such as: What is there after death?
What is the meaning of life? Does God exist? What about our free will? While
such questions are as old as the hills, we keep discussing them using the
jargon of the cultural environment in which we grew up, with words and non-dits that are peculiar to our own clan.
It is now time
to use a common language in addressing such questions. One can no longer ignore
what other clans are teaching us. Wearing blinkers does not make one see
better. For us, laymen venturing beyond the borders of our own clans, the
details of the lessons that the members of other tribes are teaching us are
unimportant. What matters is to extract the essential, the main substance, and
to try hard to be as faithful to it as possible, to
prevent our glasses from distorting its outline. The main message of
contemporary biology, and in particular of neurosciences, is what Francis Crick
was modestly calling in 1994 ‘the astonishing hypothesis’, which one would
probably be entitled today to rename ‘the astonishing evidence’ as it has since
been corroborated by such a host of new observations: it is the physics and
chemistry of our cells which govern our bodies and our minds, our feelings,
emotions and consciousness.
Many refuse to
accept such a hypothesis, arguing that the picture of the world which science
has drawn for us is neither clear nor complete. They are right, many dark areas
still subsist. But time has come to take this picture seriously. The reader is
not supposed to accept it but only to accept, as an intellectual exercise, to
spend a few minutes in exploring its implications. Our natural difficulty to assimilate
new ideas should not make us wear a pretentious mask of enlightened scepticism
that would simply hide our ignorance.
The use of
different jargons in addressing metaphysical issues is often seen as an asset,
an illustration of the richness of human mind. When different conclusions are
being reached, one praises the diversity of the views that such questions are
stirring up. While probably politically correct, such an attitude is
intellectually unacceptable. Diversity is not a goal in itself. If praising
diversity simply means praising tolerance and open-mindedness, fine, I am for
it. But if Peter tells you that two plus two make four and Paul that two plus
two make five, the idea of praising the diversity of their views will not come
to your mind. What neurobiologists and neuropsychologists teach us is the
result of thousands of rigorous observations and of skillful analyses and interpretations [1]. They argue in a general framework that keeps establishing itself
stronger and stronger: that of evolution, of molecular biology and of genetics.
Before doubting their arguments, one better makes sure to understand them well.
We who listen
to dialogues between members of different clans, we must learn to spot possible
disagreements having their origin in the ignorance that one of the tribes has
of facts which the other masters. To the extent that such facts are relevant,
it is easy to choose whom to listen to.
We must undertake
our exploration with an open mind in order to learn from others rather than
looking around through the filters of our own field. The recent advances in
neurosciences impose a radical revision of the traditional approach that has
been developed by philosophers who left a deep imprint on the history of ideas,
such as Plato, Descartes, Leibniz, Spinoza or Kant. Being familiar with the way
they have argued and with the systems of the world which they have constructed
is of course an asset, however of little help to assimilate the new ideas. Of
as little help as Schrödinger's cats, Gödel's incompleteness theorems and
Turing's test, which are often invoked in other circles.
I have chosen
to expand on two themes which seem to me particularly well suited to the aim. One,
free will, is an excellent illustration of the upheavals caused to the
traditional way of thinking about major metaphysical questions by the recent
discoveries of contemporary neurosciences. The other, circularity of knowledge,
helps to clarify the limits of knowledge and to better mark its boundary with
metaphysical and religious beliefs. Both bump deeply into our common sense and their
assimilation requires a major effort of reflection. Both are equally important
and compel us to revise radically the concepts with which we used to construct
our argumentation: the self, body and mind, subject and object, concrete and
abstract, real and ideal, conscious and unconscious, and many others.
On free will
Free will, and
its apparent incompatibility with scientific determinism, provides a
particularly clear illustration of what the new ideas imply. In the past fifty
years, molecular biology, genetics and neurosciences have made spectacular
progress that command respect ; they draw the picture of a man who can be
fully described in terms of the atoms which he is made of and of their
interactions, a ‘neuronal man’ as J.P. Changeux says. Our acts, thoughts,
feelings, emotions, creations can all be explained − meaning described
− in terms of the interacting atoms which our brains are made of.
We must always
keep in mind the continuous evolution of the brain from embryo to adult and
from earlier species to ours. In this process, the brain gets organized and
structured with the aim of putting more and more order in the signals that it
keeps receiving. Such organization and structuring, accurately coded in the
genome in the course of evolution, allow the newborn baby to start elaborating
some elements of logics, to establish relations, to identify objects and follow
them in time, to draw an image of space and time, and so on. At the same time, the
education from parents and teachers, together with acquired experience, help in
building a sum of knowledge that gets organized according to a common general
scheme. A minor part, but essential for the conduct of our life, is accessible
to our memory, which is able to recall it; the rest is not − it may be
partly revealed on the occasion of dreams or traumas − but obviously plays
an important role.
The
materialism of such a picture should not make us see the brain as well oiled
clockwork or as a supercomputer. Both models can only cause confusion. The brain
is alive, it keeps changing, it keeps reshuffling, going over and checking
through the information that it has in store. Its plasticity, its ability to
handle multiple information in parallel, to interact with the signals that it
keeps receiving, to generate images to be used later on as references, are
among its most remarkable features.
It is now time to address the question of free will,
hoping that its study might shed light on the picture we have of the brain. Let
us define the problem as simply as we can. You have decided to raise the right
arm; only you know that it is the right arm and not the left arm that you
decided to raise; and you raise it. You might have decided to raise your left
arm instead, and you would then have raised your left arm. Apart from you, no
one can know in advance which had been your decision. You are free to decide
which arm you will raise. Yet, if one believes the picture of the world which
science is drawing for us, all your movements in the time interval that starts
a few seconds before you took your decision and that ends a few seconds after
you raised the arm, are subject to the laws of physics and, therefore, predetermined: once the initial state is known (before
decision taking) the final state can be uniquely deduced from it.
[a]
The contradiction is obvious and kind of baffling, even for scientists:
remember Jean Hamburger admitting that if our spiritual world is only a matter
of the physics and chemistry of a tangle of neurons, if their determinism is
hiding behind each instant of our mental life and governs them secretly, “we
may as well forget about our freedom of thought. We may as well forget about
our freedom of choice” [2]. It bewilders philosophers, even those, as John
Searle, who are well-disposed towards science:
“Ideally, I would like to be able to keep both my commonsense conceptions and
my scientific beliefs [...] But when it comes to the question of freedom and
determinism, I am − like a lot of other philosophers − unable to
reconcile the two” [3]. Finally, its emotional load is enormous:
remember Dostoyevsky predicting that science will transform human beings into
piano keys or organ pull tabs the day it will tell them “that, to say the truth, they have neither will nor whims of their own; that,
by the way, they never got any […] and that, to top it all, there exist laws of
nature; so that all what they do is not the result of their will but happens on
its own, in conformity with such laws” [4].
Let us try to identify what the problem consists in. There is no problem
with taking a thought-out − or better, well motivated − decision.
It is easy to imagine the mechanisms that are at play, even if one does not
understand the details. Take the example of a thirsty donkey, a cousin of that of Buridan, standing in front of two buckets,
one empty and the other full of water; it will promptly see the buckets, notice
that one is empty and the other full, decide to reach the latter and drink. Its
brain will have made a choice between two possible futures (among many others):
to go to the empty bucket or to go to the full bucket. A donkey is, no doubt,
able to make such choices. Much more simply, most micro organisms are able to
move along the concentration gradient of what they use to be fed from,
sunflowers are able to follow the path of the sun; in such cases, one cannot
talk of decisions, there is no need for a brain. Yet, the decision of the
thirsty donkey is in the wake of such tropisms, its brain being simply a much
more complex and subtle tool than those used by the amoeba and by the heliotrope.
Such a ‘decision’ is not in direct conflict with the laws of physics: one might
imagine a sophisticated robot taking it.
Let us now assume that both buckets are initially full. Then, according
to the laws of physics, the donkey should die of thirst for being unable to
make a choice: making a choice would break the symmetry of the problem. Yet,
whatever Buridan might have thought, it is a safe bet that the donkey will pick
a bucket and drink out of it. Of course, in practice, it will always have a small
reason to prefer one to the other (it is closer, it smells better...), but this
is not what we are concerned with here. We assume that the buckets are strictly
identical and that the problem is perfectly symmetric. From a scientific point
of view, it should then be impossible to make a choice. Moreover, from such a
point of view, there is no difference between a donkey and the ‘neuronal man’
implied by Crick’s ‘astonishing hypothesis’: our free will is in obvious
conflict with scientific determinism.
For centuries, the paradox had been discussed in philosophical terms but
it is only recently that neurosciences have shed such new light on it, causing
much of the earlier debate between compatibilists and non-compatibilists, soft
and hard determinists, physicalists and libertarians to be superseded [5]. What
was wrong, in our reasoning, was the implicit assumption that the donkey’s
brain obeys the symmetry of the problem. It obviously does not, it is what it
is, the result of its evolution from the time when the donkey had been
conceived by its parents. As we shall see, this leaves room for processes that
allow for making a choice without violating the laws of physics.
One must never forget the unbelievable complexity of the brain, its
characteristic plasticity and the swarming activity that it shelters. Its role
is determinant; one may not ignore it when talking of an initial state. The
immense majority of the operations it is executing are not accessible to our
consciousness. Our thoughts and the consciousness we have of ourselves −
of our self − are part of the tiny minority of those that are. In
particular, our consciousness has no access to most of the mechanisms which govern our choice making and decision
taking; our brain keeps preparing choices in order to decide on our future
actions without us being aware of it; eventually, the final decision may have
to account for other possible choices of which we are conscious, and in the
development of which we have consciously taken part; such thought-out choices,
if they are present, will get priority; but in the absence of such choices, in
some sense by default, what the brain had prepared will become a decision and
action will follow accordingly. In this sense, the brain is able to make
choices ‘of its own’; indeed, too long an hesitation is never very good for the
survival of a species and it would not come as a surprise that evolution
favoured such an aptitude. These ‘default’ choices have been prepared by the
brain without us being conscious of it; our consciousness only knows about the
outcome. As a minister, who only needs to sign the file that has been prepared
for him by his cabinet, has the impression, when signing, to be taking a
decision, our conscious self believes that it has decided what our unconscious
self prepared for him in the dark. For having ignored it, we had wrongly
concluded that determinism and free will were incompatible. How it works in
practice is far from being understood in all details but scientists such as G.
M. Edelman or A. R. Damasio [1] have drawn for us possible scenarios.
[b]
How the donkey’s brain decides to favour the bucket on the left rather
than that on the right is not a problem: even if the external symmetry of the
problem is perfect, information of relevance, such as the various ‘representations’
of the buckets, are stored in the donkey’s brain in a non-symmetric way; for
example, the image of the bucket that was seen first is likely to have been
centrally processed before the other.
When you have decided to raise the right arm, you have in fact become
conscious that such was the choice which your brain was presenting; you were
equally conscious of the possible reasoning that had contributed to your choice;
but you were not conscious of other operations that had also contributed. Under
such conditions, it does not come as a surprise that the choice appears to you
as resulting from what you feel is your decision: you can only perceive your
self through what you are conscious of. The apparent paradox was not with the
laws of physics but rather with this impairment which is (fortunately!) preventing
us from being aware of the whole activity of our brain. The feeling we all
have, when we make a choice or take a decision, that our free will implies
something else than the laws of nature is indeed an illusion. Whether free will
itself is or not an illusion is a matter of defining more precisely what we
mean by free will now that we better understand the mechanisms of choice making
and decision taking. Had we understood it before coining a name, we probably
would have chosen other words: ‘free’ might have sounded too arrogant in such a
context.
It is easy to say the same thing in a less aggressive way. It is
sufficient to modify the meaning that we give to ‘I’ or to ‘self’,
to simply agree that, for what concerns the activity of our brain, the self
does not simply cover what we are conscious of but the whole of it. Then, yes,
we may say ‘I’ have
decided, ‘I’ have chosen. It is
now the words ‘to choose’ and
‘to decide’ that have lost
their original arrogance. ‘My choice’ and ‘my decision’ simply obey
the laws of physics. No need any more for a so called free will coming down
from God knows where, as a deus ex
machina, in order to change the course of the world. And that does not turn
me into a piano key or an organ pull tab since there is no one to play the
piano and the organ. This ‘I’ is made of all ‘my’ past: ‘my’ knowledge, ‘my’ experiences, ‘my’
thoughts, ‘my’ interactions with ‘my’ environment. There is a long way between
this self and the self that was suggested by Descartes’ “idées claires et distinctes”: they turned out to be sources of
illusions.
Sometimes, those who ignore scientific advances get themselves cheaply a
clear conscience by claiming, with Bouveresse, that metaphysics arguments are
about something else, something “of another kind”. The honest man refuses
taking such a claim seriously. It reminds me of these textbooks in philosophy
of science (alas, they are still in use!) which state that science makes
calculations without understanding them but that philosophy is here to understand
what is hiding behind!
I chose to talk on free will but I might as well have chosen many other
topics which would have been as apt to reveal the upheavals that science is
causing to the traditional approach of major metaphysical questions. I might
have talked on pain or on artistic creation the result would have been the same:
a drastic revision of traditional concepts.
Before closing
this section, I should say a few words on the ethical side of the question. Ethics
and metaphysics are not the same thing but they often lead to reflections that feed
each other; this is particularly true in the case of free will. Becoming
conscious that the feeling we have about free will is an illusion triggers
often comments that reveal a deep misunderstanding of what science is teaching
us, such as “As everything is written in advance, I cannot be held responsible of my actions ; I may therefore kill as I please.” Such a statement implies a
complete misunderstanding of what ‘I’ means ; it implies the belief that the common sense ‘I’, the ‘I’ which science has just made obsolete, the deus
ex machina, is still around, ready to make use of his free will in order to
decide to kill as he pleases.
Another common
misconception is to think that two distinct selves reside in our brain, the
conscious self and the unconscious self, each able to make choices and take
decisions, the conscious self being morally responsible and the unconscious
self being not. This misconception is the result of misunderstanding what is
meant by conscious self. There is only one self, but our consciousness has
access to only part of what it is made of. There is only one step in the chain
of processes leading to a choice to be made where the choice is actually made,
the decision actually taken. But some of the processes that led to this choice
are accessible to our conscience, others are not.
What science
is teaching us is the death of the obsolete idea we used to have of our self. Our
new ‘I’ came into existence
when the egg from which we were born got fertilized. Since then he kept being
enriched by new experience, acquiring new knowledge, thinking, making choices
and taking decisions. He did all this thanks to the amazingly efficient and complex
tool which our brain is. He obeys the laws of nature, which, incidentally, he himself
and his kind have been developing. Our muscles and guts obey the laws of
nature, no one complains; our brain obeys the laws of nature, one feels
offended. We must dispose of this slightly ridiculous picture of a
supernatural, quasi divine ‘I’,
who was able to intervene on the course of our life from outside (but which
outside?). It is such a picture which is the illusion.
The fact that
the new ‘I’ obeys the laws of
nature does not make ‘me’ irresponsible
toward the society. The society is a set of individuals like me, their thoughts
and actions obey the laws of nature. We all feel that, when we make a choice or
take a decision, we somehow escape the tyranny of the laws of nature. If we share
this illusion, we need an ethics well suited to such illusion, don’t we? Of
course, for whom wishes to talk about responsibility toward some God, it is a
different matter. But the scientific point of view does not lead to an ethics
of irresponsibility. It simply suggests us being more modest and humble than we
thought being entitled to be.
The circularity of knowledge
While free will has been and still is extensively
debated by philosophers in relation with the recent findings of neurosciences
[5], the topic that I am now addressing is not. It brings up questions that
have been discussed by philosophers for centuries, not to say millenia, and
that are considered today as commonplace bread and butter philosophy. They now
need to be rethought by taking due account of the new vision of the world that
contemporary science is providing us with. In so doing, even more than in the
case of free will, we must be attentive not to be imprisonned in the words and
concepts that we have been using all along. The temptation to keep referring to
earlier philosophers is strong, but earlier philosophers were unaware of
contemporary science and whatever they have written, as deep and brilliant as
it might be, needs to be reconsidered in the light of recent findings.
The new vision of the world which contemporary science
is providing us with also implies a new vision of the nature of scientific
knowledge, often quite different from that given by traditional epistemology.
It is therefore useful to spend a few lines in sketching it.
Who is not familiar with contemporary physics often mixes
it up with mathematics and sees nothing in it but cabalistic formulas without
any relation to the real world.
As Feynman wrote, mathematicians prepare abstract reasoning
ready to be used by the physicist who describes the world and must give a
meaning to each of his sentences: “It
is something very important that many of those who come to physics from
mathematics do not understand. Mathematicians help physicists. But in physics
you must understand the relationship between the words and the real world” [6].
Mathematicians, like those who came to physics from mathematics, make indeed a clan
of their own. The members of other tribes often mistake them for the archetype
of a physicist.
In order to well understand the circular nature of
knowledge, it is necessary to first dispose of prejudices that are often attached
to the notions of theory, observation and abstraction [7]. Take as an example
the observation that the sun sets in the west. One easily gets convinced that
this is not an observation but indeed a theory. Speaking of the sun implies
having imagined that the red circles, which one sees disappear each clear
evening behind the horizon, are one and the same thing which one sees reappear
each clear morning on the other side; naming the sun implies having already a
theory of the sun. Speaking of the west implies having learned to define a
direction despite appearances (seen from here, the sun sets on the right of the
tall pine tree on top of the hill, but seen from a bit farther away, it sets on
its left), naming the west implies having already learned some geometry. What I
mean, is that as soon as we undertake a description of what we observe, we
start transforming the raw data of the observation into sentences, numbers,
information that our brain keeps in memeory and that are already making up a
theory.
It is often said that the role of a
physical theory is to relate among themselves the quantities used to describe
phenomena, the observation of which one attempts to give an account of. But
such a statement implies essential preliminaries, the identification and definition
of such quantities. It is in this preliminary step, if anywhere, that one may
see abstraction. Whether one speaks of material points, vectorial forces,
space-time quadrivectors, Hilbert space vectors or superstrings, such
quantities are not a priori obvious objects, they first need to be
conceived in the brain of a scientist. It is worth pointing at the ad hoc,
not very rigourous nature of this abstraction process which is the preliminary
phase in the elaboration of any physical theory. The completed theory is
sometimes so elegant and apparently perfect that one may tend to forget it. It
would be a major mistake to let oneself get dazzled and to erect the theory
into absolute truth. One must always be ready to revise the bases on which it
has been built if new bases make it possible to construct a better one, more
general or more accurate.
Classical mechanics is not as good a theory as special
relativity but it is not less abstract. It only seems so to whom is so much at
home with it, that it kind of became its common sense: he forgot that it too
was resting on abstractions. Very often, criticizing science for being too
abstract simply reveals the difficulty we have in racking our brains.
It makes no sense to criticize a theory because it is
too abstract: all theories, even the simpler among them, are abstract; indeed,
their role is precisely to abstract. One should not either criticize a theory
because it goes against common sense, common sense is nothing but the theory
that has been previously assimilated; its reality is purely subjective, even
though such subjectivity is usually collective. It is nothing but the theory
that has been assimilated by the majority. Science is always ready to accept a
new theory, whatever effort of abstraction it may require, as long as it is
better than its predecessor. As an obvious corollary, it gives up any claim at
reaching some absolute truth.
The fascination of mathematics is blatant. You start
from apparently innocent hypotheses and you discover an unexpected and
wonderful universe. In the same way as language makes it possible for us to
play with words and to create magic worlds, mathematics make it possible for us
to play with axioms and to create a whole hierarchy of infinites, Peano curves,
undecidables and so many other wonders. Such is the way they are made: the
contrast between their richness and the simplicity of the hypotheses at their root
is amazing; as are the beauty and elegance of their constructions and the
feeling of purity that they convey. In contrast with science, which depends on
the phenomena that it tries to understand and to explain, mathematics succeed
to free themselves by making axioms out of the little bits of help that nature
gives them to start their explorations in the right direction. While science must
constantly revise its hypotheses, mathematics are immortal. And like philosophy
had parted from science because it did not accept limiting its scope to
phenomena, mathematics have parted from science because they could aspire to
dispose of phenemena.
What is known about the genesis of the brain, whether
at the level of the individual or at that of the species, suggests that
mathematics and logics owe much more to phenomena than one had thought up to
the middle of the twentieth century. It was then often implicitly accepted that
logics was there first. Ab initio erat
Verbum. Logics, Verbum, Logos…But it is difficult, today, to imagine logics
as being wholly coded in our genes. At which stage in the evolution would such
a coding have appeared? Of course, some of the aptitudes required for the
elaboration of logical reasoning are innate, there is no reason to doubt it.
But no more nor less than some of the aptitudes required for the elaboration of
language. When, after one week or so, the newborn baby has succeeded to
elaborate a ‘theory’ of his mother – having established correlations among the
many images of her smiling face that he has kept receiving, and having
associated them with the sound of her voice that he was already hearing before
being born – hasn’t he already developed several fundamental concepts of
logics?
The reader, by
now, should have disposed of some of the prejudices he might have had [7]. But
the more difficult part, understanding the circular nature of knowledge, is
ahead of us. We first need to define more precisely what we mean by knowledge.
Anything we know results in elements of information that our brains have in
store and keep reshuffling. Incidentally, we may talk of us collectively, at
the scale of the whole species, as such an important role is played by culture,
namely by the ability enjoyed by the members of our species to communicate and to
exchange knowledge. Much knowledge belongs to single individuals, such as ‘this
morning, when I woke up, I saw a bird sitting on the window-sill; no one else
could have seen it’. Such knowledge is uninteresting in the context of the
present discussion, we may include it or not in what we call the knowledge of
the species, it is unimportant.
If we mean by knowledge
anything that is stored in the brains of our species, there exists a single
form of knowledge. Of course, one may make a distinction between the knowledge
that we acquired from our own experience and that which we learned or inherited
from our parents and teachers; or between that we may have of biology and that
we have of our emotions; or between that which we express under the amazingly
dense and concise form that mathematics are providing and that which we express
with everyday phrases. Such distinctions are irrelevant for what we are
concerned with here. We would be playing with words if we were, at this stage,
bringing up the knowledge we learn from a poem, a sonata, the friendship of a
child, the love of a woman, the example of a hero, the wisdom of a teacher, the
beauty of a sunset. Such knowledge also results in pieces of information which
our brains keep in store. It may have a particularly strong impact on our
personality and deeply contribute to our way of leading our lives, but this
does not change a thing to its nature. We would also be playing with words if
we were contrasting the knowledge we may have of quantum theory, of souls, of
our wishes and sorrows, of the taste of wild strawberries or of the smell of
pine trees.
Yet, to make
my point clear, I need to make a distinction between knowledge and belief. I
live in a country where most people believe that we have souls and that the
souls of their dead ancestors are still among us; each fortnight, when the moon
changes phase, they offer them fruits and other goodies and burn incense sticks
in order to please them. It is not trivial to tell such beliefs apart from
knowledge: both are stored in the brains of many individual of our species. In
order to make such distinction, we need to deal first with scientific
knowledge.
Scientific
knowledge is nothing but a story that scientists tell us, a story that aims at encompassing,
in as simple terms as possible, as much as possible of the information that has
been collected by our brains and by those of our ancestors. Their claim of being
able to describe reasonably well the time evolution of the world gives them the
ambition to include what preceded in the story: big bang, inflation, the
formation of atomic nuclei, that of atoms and, much later, of the first
molecules of life, of the first cells, of the first living organisms, the
development of their central nervous system until it became the brain that our
species is hosting, the elaboration and tuning of logics, language and
mathematics that we are using to describe in simple terms − we say to
explain − what we are observing and experiencing.
We tell such a
story as if we were observing an external world from outside, it helps making
the story simple. We do as if such a world existed, as if we were around,
observing it and describing it. But what do we precisely mean when we talk of
the existence of such a world? We are, of course, both subjects and objects; we
are part of the world that we are observing. It would indeed be more proper to
talk of a world observing itself, with the brains of our species playing the leading
role. It is quite tempting to infer that this world would exist even if we were
not around. It is indeed what we claim: our species appeared very late in the
world history; not only the world is meant to have existed well before our
apparition but we feel able and entitled to describe what it then looked like
as if we had witnessed it.
But what do we
mean when we say ‘to exist’? Nothing
but ‘to be part of the story that we are telling’. All
we know boils down to that story. If that is what we meant, we were right to
say that the world existed before us being around to observe it: it is precisely
what is being told in the story. But we should refrain from giving such
existence a deeper meaning. Our claim to be able to describe the world
independently from us is not an excuse to forget that the story we are telling
is nothing but the result of setting in order the information which our species
has been accumulating over the years to build up its knowledge. One may at this
stage be starting to grasp the circularity of such knowledge all we know is
what the brains of our species have been learning, nothing else. They have
learned it by setting in order the information they have received from the
world. But such sentences make only sense within the story. It is the story
that tells us about brains, about a world and about information being received.
Such concepts owe their existence to the story exclusively. We are telling a
story that is telling how we are telling a story that is telling how...A
perfect auto-reference loop in which we are inescapably imprisoned. The
circularity of knowledge prevents us from giving any meaning to statements that
claim to be able to escape it.
We are trying
to understand phenomena globally and we are using words, sentences, rules and
laws in order to describe them. Such rules and such laws, whether of logics or
of science, are nothing but our way to convey such understanding and
descriptions, nothing but our way to express the phenomena. Logics and science
are wholly contained in the phenomena and the phenomena wholly contained in
logics and science. I say ‘science’ but I might as well say ‘knowledge’,
implying the totality of the scientific knowledge accumulated over the course
of time.
Auto-reference confines knowledge within its loop, but, by the same
token, makes any discussion that claims to escape it meaningless. By definition,
anything outside the loop is inaccessible to us; we are even unable to give a
meaning to the phrase ‘outside the loop’. The story that we are telling is so
simple, so coherent, that it is tempting to forget its auto-referential nature
and to yield to the metaphysical illusion: shadows on the wall of Plato's cave
can be nothing but the image of an external reality. The real world would
precede us, be already there and ready to welcome us: the door is open to the
founding myths of our legends and religions. But our only knowledge is unable
to embody such an illusion. To do so, we need to postulate something else than
what we know, taking the form of metaphysical doctrines or of religious beliefs
that make it possible for us to escape the auto-referential loop and to explore
the virgin land outside its circle. Of course, we have the right to do so as
long as we do it knowingly.
What I am saying here differs from the arguments that have been used
over the centuries by proponents and opponents of realism. Such arguments do
not question the possibility to define an external reality but are concerned
with its existence. The point here, in the light of what has been learned from
modern science, is that it simply makes no sense to talk about an external
reality if we stick to what we know. There cannot be a debate between proponents
and opponents of something that cannot even be defined. The crucial point is
the ability to differentiate between what is inside the auto-reference loop and
what is outside. If Peter sticks to the inside, which he calls knowledge, he
should refrain from talking about an external reality. On the contrary, if Paul
escapes outside, into the land of beliefs, he is of course free to believe
whatever he likes and to talk about it. Paul might even argue that both his
knowledge and his beliefs are stored in his brain and that there is no reason for
him to tell them apart. Peter has nothing to oppose to such an argument and
there is indeed nothing wrong with it. What makes their views differ is the
simple fact that one refuses and the other accepts to escape the auto-reference
loop. It is clear to both of them and they can remain good friends without
having to change their views. I said earlier that I would come back to the
distinction between knowledge and belief, it is now done.
But let us stick, for the time being, to what we know and let us try to
better understand the nature of the illusion. The illusion is not to believe in
the pre-existence of the real world but to believe that we can give a meaning
to such a phrase, a meaning deeper than what auto-reference implies. The point
is not to claim that the world did not exist before us being around, a kind of
solipsism at the world scale, but to make it clear that such a claim is
meaningless. We simply must restrain ourselves from giving to the verb ‘to exist’ a deeper meaning than is implied by the story we are
telling.
Many scientists, in the wake of Dirac and Wigner, marvel at the beauty
of mathematics and at their miraculous ability to give such an accurate
description of nature. With Einstein, they express surprise that the universe can
be understood. With Chandrasekhar they wonder “how the human mind can imagine some abstract concepts and find them beautiful;
and why such concepts find their exact equivalent in nature” [8]. Implicitly,
and more or less consciously, they use the third-person when talking about
nature, as if they were looking at it from the standpoint of a Creator. But how
could a self-observing world speak of itself other than by using the
first-person? As logics and mathematics were forged by the world precisely with
the purpose of observing and describing itself, what point is there to marvel
about their miraculous efficiency? Which yardstick should we be using in order
to evaluate to which extent this is a miracle?
When scientists themselves yield so readily to the
illusion of an external reality, it is easy to imagine that those who are less
acquainted with science will be even more willing to yield to it. For many, the
existence of an external reality is simply an evidence. The French Encyclopedists,
after having defined metaphysics as the science of the reason of things, go on
explaining that “limiting one's scope to empty and abstract considerations on
time, space, matter and mind is contemptible science: but looking at these from
the real point of view is something else” [9]. Alas, still today, many look
down upon what we know and revere what we are dreaming of. For them, what we
know is empty and abstract. The real point of view stands somewhere outside the circle, on
summits of which we know nothing.
The circularity of knowledge deprives of its meaning any attempt at
escaping the auto-reference loop. One often quotes, sometimes indiscriminately,
a famous sentence of Wittgenstein that expresses it
very well: “It is not how is the world that is
the Mystique, but the very fact that it is [...] The proper method in
philosophy would be to talk only of what can be told, namely the propositions
of natural sciences – something which has therefore nothing to do with
philosophy [...] On what cannot be told, we must keep silent” [10].
But is it so easy to keep silent about what cannot be
told? Are we forever doomed to talk of nothing else than what we know? May we
hope that some day we shall know enough to answer all our questions? Of course,
not. Let us take, as an example, one of the simplest questions that may come to
mind: ‘Why does the world exist?’ Such a question obviously stands outside the
auto-reference loop. It is therefore a question to which we are unable to give
a meaning. But are we willing to accept light heartedly to dispose of it so
easily? After all nothing is going against there being no world. Of course, we
would not be here to observe such nothingness but this does not make the
question less important. One may feel satisfied with the statement that the question
is meaningless; one still cannot help being disturbed by this observation. Close
to the question is the famous sentence by Leibniz, “There is a reason in Nature
such that something, rather than nothing, has to exist”.
Unfortunately, we are unable to give a meaning to the
question. How could we answer it? We are here very close to Descartes' cogito:
whoever may wish to fool me, I pretty well know that I exist as something that
is thinking; whoever may wish to fool me, the world might say, I pretty well
know that I exist and that I am not nothingness, I pretty well know that I
exist as something that is thinking, I mean something able to think about
itself.
What Wittgenstein calls the Mystique − may be
should we simply call it the Mystery − is much too important for us to
resign ourselves to keep silent about it. In our minds and hearts it plays much
too large a part. Having stirred up the metaphysical hornets' nest has done us
a lot of good! We have disposed of traditional concepts that had taken
centuries to be conceived, and here we are, back to square one, facing a
Mystery that we cannot even talk about...
To talk about it, we have the major systems of the
world, milestones marking out the history of metaphysics and religions. In order
to hold forth on it sensibly outside the auto-reference loop, these are calling
for acts of faith, sometimes supposedly revealed, that are the price to pay for
our evasion. Inside the loop, words such as ‘reality’, ‘truth’ or ‘existence’ are synonyms that simply mean ‘belonging
to the story that is being told’. Metaphysics and religions credit such words
with much more daring semantic ambitions. It is then important to define them
clearly and precisely to avoid discussing of the sex of angels.
In most cases, it is inside the loop that one looks for
clues which might show the way. As an example, some think that the arcane
concepts of quantum physics might be hiding possible keys; but how can they hope to find the key of the Mystery in
an illusion of commonsense? All metaphysical systems make use of the
logics that is being used inside the loop. Even religions accept it in most
cases, rarely taking the liberty of preferring a metaphor of a moral or poetic nature
to make their point. But those who wish to extend their reflection in a
metaphysical framework should not get fooled by the words they are using. They
must not only properly define the concepts − monads, God, infinity,
things-in-themselves, and so on − but also, more simply, they must state
which logics, which language they are using outside the auto-reference loop: it
is not that plain that they should be the same as inside.
Today, we no longer can afford to talk about the
Mystery as did Plato, Augustine or Descartes, in terms that ignore what has
been learned from contemporary science. Doing so would simply imply turning
over and over the same mirages and illusions.
Clearly, we are not prepared to accept light heartedly
the absurdity of human condition that is implied by our being imprisoned inside
the auto-reference loop. Camus, together with numerous contemporary thinkers, described
it well: “an implacable refusal,
contrasting with an overwhelming desire for clarity crying from deep
inside us” [11].
Knowledge
does not close the door to Mystery; its fundamental disability, auto-reference,
prevents it from answering a question which sounds to us so important: ‘Why this world rather than nothing?’ On
the contrary, it is revealing how deep the Mystery is; it makes us become
conscious of the absolute inability of knowledge to unravel it. To whom
regards as essential to know the answer to such questions, it offers the
possibility of an ethics constructed on the basis of his beliefs, on the basis
of such or such a religion or metaphysical system, the founding principles of
which he is willing to accept outside the auto-reference loop.
To whom is not ready to accept such postulates, for
example because he finds them unfounded, it tells that he will never know why
this world is here rather than nothing. He will have no other choice than sheer humanism to base his life on. That
is all he may grab hold of. Together with Camus, he will have to accept that “happiness
and absurd are both sons of a same earth, they cannot be pulled apart” and that “fighting for the top is
enough to fill a human heart, we must think of Sisyphus as being happy” [11].
Let us remember David Hume who, after having told us how frightened he
is by the solitude in which he is placed in his philosophy, comforts us
promptly by adding “Most fortunately
it happens, that since reason is incapable of dispelling these clouds, nature
herself suffices to that purpose, and cures me of this philosophical melancholy
and delirium, either by relaxing this bent of mind, or by some avocation, and
lively impression of my senses, which obliterate all these chimeras. I dine, I
play a game of backgammon, I converse, and am merry with my friends...” [12].
Acknowledgements
I wish to express my gratitude to Stephen
Morris who took the time to comment for me his views on free will and to listen
to my own. Communication between physicists and philosophers is a difficult but
rewarding exercise when it is made in a spirit of mutual understanding.
References
[2] J. Hamburger, Le Miel et la Ciguë, Editions du Seuil,1986.
[3]
J. R. Searle, Minds, Brains, Science, Penguin Books, 1989.
