Jim Holt has written
an entire book on this subject, titled Why
Does the World Exist? An Existential Detective Story. Holt is a philosopher
and frequent contributor to The New
Yorker, the New York Times and the London Review of Books, according to the blurb on the inner title
page. He’s also very knowledgeable in mathematics and physics, and has the
intellectual credentials to gain access to some of the world’s most eminent
thinkers, like David Deutsch, Richard Swinburne, Steven Weinberg, Roger Penrose
and the late John Updike, amongst others. I’m stating the obvious when I say
that he is both cleverer and better read than me.
The above-referenced,
often-quoted existential question is generally attributed to Gottfried Leibniz,
in the early 18th Century and towards the end of his life, in his
treatise on the “Principle of Sufficient Reason”, which, according to Holt, ‘…says,
in essence, that there is an explanation for every fact, an answer to every
question.’ Given the time in which he lived, it’s not surprising that Leibniz’s
answer was ‘God’. Whilst Leibniz
acknowledged the physical world is contingent, God, on the other hand, is a
‘necessary being’.
For some people (like
Richard Swinburne), this is still the only relevant and pertinent answer, but
considering Holt makes this point on page 21 of a 280 page book, it’s obviously
an historical starting point and not a conclusion. He goes on to discuss Hume’s
and Kant’s responses but I’ll digress. In Feb. 2011, I wrote a post on
metaphysics, where I point out that there is no reason for God to exist if we
didn’t exist, so I think the logic is back to front. As I’ve argued elsewhere
(March 2012), the argument for a God existing independently of humanity is a
non sequitur. This is not something I’ll dwell on – I’m just putting the
argument for God into perspective and don’t intend to reference it again.
Sorry, I’ll take that
back. In Nov 2011, I got into an argument with Emanuel Rutten on his blog,
after he claimed that he had proven that God ‘necessarily exists’ using modal
logic. Interestingly, Holt, who understands modal logic better than me, raises
this same issue. Holt references Alvin Platinga’s argument, which he describes
as ‘dauntingly technical’. In a nutshell: because of God’s ‘maximal greatness’,
if one concedes he can exist in one possible world, he must necessarily exist
in all possible worlds because ‘maximal greatness’ must exist in all possible
worlds. Apparently, this was the basis of Godel’s argument (by logic) for the
existence of God. But Holt contends that the argument can just as easily be
reversed by claiming that there exists a possible world where ‘maximal
greatness’ is absent’. And ‘if God is absent from any possible world, he is absent from all possible worlds…’ (italics in the original). Rutten, by the
way, tried to have it both ways: a personal God necessarily exists, but a
non-personal God must necessarily not exist. If you don’t believe me, check out
the argument thread on his own blog which I link from my own post, Trying to define God (Nov. 2011).
Holt starts off with a
brief history lesson, and just when you think: what else can he possibly say on
the subject? he takes us on a globe-trotting journey, engaging some truly
Olympian intellects. As the book progressed I found the topic more engaging and
more thought-provoking. At the very least, Holt makes you think, as all good
philosophy should. Holt acknowledges an influence and respect for Thomas Nagel, whom he
didn’t speak with, but ‘…a philosopher I have always revered for his
originality, depth and integrity.’
I found the most
interesting person Holt interviewed to be David Deutsch, who is best known as
an advocate for Hugh Everett’s ‘many worlds’ interpretation of quantum
mechanics. Holt had expected a frosty response from Deutsch, based on a review
he’d written on Deutsch’s book, The
Fabric of Reality, for the Wall
Street Journal where he’d used the famous description given to Lord Byron:
“mad, bad and dangerous to know”. But he left Deutsch’s company with quite a
different impression, where ‘…he had revealed a real sweetness of character and
intellectual generosity.’
I didn’t know this,
but Deutsch had extended Turing’s proof of a universal computer to a quantum
version, whereby ‘…in principle,
it could simulate any physically possible environment. It was the ultimate
“virtual reality” machine.’ In fact, Deutsch had presented his proof to Richard
Feynman just before his death in 1988, who got up, as Deutsch was writing it on
a blackboard, took the chalk off him and finished it off. Holt found out, from
his conversation with Deutsch, that he didn’t believe we live in a ‘quantum computer
simulation’.
Deutsch outlined his
philosophy in The Fabric of Reality,
according to Holt (I haven’t read it):
Life and thought, [Deutsch] declared, determine
the very warp and woof of the quantum multiverse… knowledge-bearing structures
– embodied in physical minds – arise from evolutionary processes that ensure
they are nearly identical across different universes. From the perspective of
the quantum multiverse as a whole, mind is a pervasive ordering principle, like
a giant crystal.
When Holt asked
Deutsch ‘Why is there a “fabric of reality” at all?’ he said “[it] could only be
answered by finding a more encompassing fabric of which the physical multiverse
was a part. But there is no ultimate answer.” He said “I would start with the
principle of comprehensibility.”
He gave the example of
a quasar in the universe and a model of the quasar in someone’s brain “…yet
they embody the same mathematical relationships.” For Deutsch, it’s the
comprehensibility of the universe (in particular, its mathematical
comprehensibility) that provides a basis for the ‘fabric of reality’. I’ll
return to this point later.
The most insightful aspect
of Holt’s discourse with Deutsch was his differentiation between explanation by
laws and explanation of specifics. For example, Newton’s theory of gravitation
gave laws to explain what Kepler could only explain by specifics: the orbits of
planets in the solar system. Likewise, Darwin and Wallace’s theory of natural
selection gave a law for evolutionary speciation rather than an explanation for
every individual species. Despite his affinity for ‘comprehensibility’, Deutsch
also claimed: “No, none of the laws of physics can possibly answer the question
of why the multiverse is there.”
It needs to be pointed
out that Deutsch’s quantum multiverse is not the same as the multiverse propagated
by an ‘eternally-inflating universe’. Apparently, Leonard Susskind has argued
that “the two may really be the same thing”, but Steven Weinberg, in
conversation with Holt, thinks they’re “completely perpendicular”.
Holt’s conversation
with Penrose held few surprises for me. In particular, Penrose described his 3
worlds philosophy: the Platonic (mathematical) world, the physical world and
the mental world. I’ve expounded on this in previous posts, including the one
on metaphysics I mentioned earlier but also when I reviewed Mario Livio’s book,
Is God a Mathematician? (March 2009).
Penrose argues that
mathematics is part of our mental world (in fact, the most complex and advanced
part) whilst our mental world is produced by the most advanced and complex part
of the physical world (our brains). But Penrose is a mathematical Platonist, and
conjectures that the universe is effectively a product of the Platonic world,
which creates an existential circle when you contemplate all three. Holt found
Penrose’s ideas too ‘mystical’ and suggests that he was perhaps more
Pythagorean than Platonist. However, I couldn’t help but see a connection with
Deutsch’s ‘comprehensibility’ philosophy. The mathematical model in the brain
(of a quasar, for example) having the same ‘mathematical relationships’ as the
quasar itself. Epistemologically, mathematics is the bridge between our
comprehensibility and the machinations of the universe.
One thing that struck
me right from the start of Holt’s book, yet he doesn’t address till the very end,
is the fact that without consciousness there might as well be nothing.
Nothingness is what happens when we die, and what existed before we were born.
It’s consciousness that determines the difference between ‘something’ and
‘nothing’. Schrodinger, in What is Life?
made the observation that consciousness exists in a continuous present.
Possibly, it’s the only thing that does. After all, we know that photons don’t.
As Raymond Tallis keeps reminding us, without consciousness, there is no past,
present or future. It also means that without memory we would not experience
consciousness. So some states of unconsciousness could simply mean that we are
not creating any memories.
Another interesting
personality in Holt’s engagements was Derek Parfit, who contemplated a
hypothetical ‘selector’ to choose a universe. Both Holt and Parfit concluded,
through pure logic, using ‘simplicity’ as the criterion, that there would be no
selector and ‘lots of generic possibilities’ which would lead to a ‘thoroughly
mediocre universe’. I’ve short-circuited the argument for brevity, but,
contrary to Holt’s and Parfit’s conclusion, I would contend that it doesn’t fit
the evidence. Our universe is far from mediocre if it’s produced life and
consciousness. The ‘selector’, it should be pointed out, could be a condition
like ‘goodness’ or ‘fullness’. But, after reading their discussion, I concluded
that the logical ‘selector’ is the anthropic principle, because that’s what
we’ve got: a universe that’s comprehensible containing conscious entities that
comprehend it.
P.S. I wrote a post on The Anthropic Principle last month.
Addendum 1: In reference to the anthropic principle, the abovementioned post
specifies a ‘weak’ version and a ‘strong’ version, but it’s perhaps best
understood as a ‘passive’ version and an ‘active’ version. To combine both
posts, I would argue that the fundamental ontological question in my title,
raises an obvious, fundamental ontological fact that I expound upon in the
second last paragraph: ‘without consciousness, there might as well be nothing.’
This leads me to be an advocate for the ‘strong’ version of the anthropic
principle. I’m not saying that something can’t exist without consciousness, as
it obviously can and has, but, without consciousness, it’s irrelevant.
Addendum 2 (18 Nov.
2012): Four months ago I wrote a comment in response to someone recommending Robert
Amneus's book, The Origin of the Universe; Case Closed (only available as
an e-book, apparently).
In particular, Amneus
is correct in asserting that if you have an infinitely large universe with
infinite time, then anything that could happen will happen an infinite number of times, which explains how
the most improbable events can become, not only possible, but actual. So mathematically, given enough space and time, anything that can
happen will happen. I would contend that this is as good an answer to the
question in my heading as you are likely to get.