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.
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.