Four Threads Unify Reality

I said in the previous post that I owed David Deutsch’s “Fabric of Reality” a thorough review – well in my usual style I won’t have time for that, but I can now precis my impression of his main messages, having just finished reading it over dinner.

Excuse some repetition with the couple of other blogs on this, but this book is worth it IMHO. This gonna be a long, but hopefully not too rambling, post. I’ve been excited since the introductory chapter, and not disappointed since – it covers, and necessarily exceeds, my own thesis very well, but is by any measure a must read book.

David’s fabric of reality is woven from four threads of thought. Four threads which individually suffer from a common problem, but which together form the basis of a startlingly credible understanding of life, the universe and everything. Published in 1997, St Douglas of-the-whooshing-deadline Adams (RIP) said simply “A tremendously exciting book” – but I didn’t notice that until after I’d read it myself. When I set out on this quest, I carefully warned myself of the trap of seeing a “model of everything” on the horizon – now I’m not so sure it is a trap.

I’ve often quoted William James warning that every generation see’s age old issues as new problems and oportunities “of our time”- hype that goes back at least five thousand years in citable references. In Deutsch’s own words his thesis is conservative, offering no startling change to the current best state-of-their-art explanations in their fields. Yet he says “I hope we shall not have to spend too long looking backwards….. It’s time to move on.” to a brave new world.

The common snag with the four main threads is that they are schools of thought that are pragmatically (instrumentally) accepted as best working explanations in their own fields, yet not only do they draw sceptical and offensive counter-attacks from the world at large, they are not easily accepted as prevailing world-views even by those practicioners that regularly depend on them.

These four ideas suffer an explanatory gap of which intutive common sense is sceptical …

(1) Karl Poppers Epistemology – that the truth of what we know about the world is based on argument in response to problems we already see, rather than any absolute logical induction of any kind.

(2) Hugh Everett’s Quantum Multiverse – that the best explanation of quantum behaviour, including interference, is the reality of many worlds – the multiverse, conveniently ignored by black box quantum recipes like the Copenhagen Interpretation.

(3) Alan Turing’s Universal Computing Machine – that finite physical resources make tractable the computation of any problem with a solution in the physical world, with two corollaries – firtsly that there are no solutions (or any kind of mathematics) not in the physical world, and secondly that virtual reality can behave as and only as any physical reality.

(4) Darwinian / Dawkins’ Evolution – that the existence and complexity of life is a matter of information replication – fundamentally nothing more, nothing less. Terrestrial life being constructed on a substrate of physics and chemistry does not mean that complex, emergent life is any less fundamental than any of the above concepts.

What Deutsch does is show how each of the above is explainable in terms of some combinations of all or part of each of the others – that together they form a consistent explanatory whole “better” than any other available models. Despite each having an explanatory gap, they plug each other’s gaps to form a whole.

Deutsch hammers Thomas Kuhn’s “paradigm shift” explanation of why each of the individual theories fails to assert itself as the accepted paradigmatic world view – the conservative defense mechanisms and (tendency to) schematic blindness that preserve old views. Kuhn’s view is I guess a grotesque pastiche of a collection of no particular real scenarios, so Deutsch is maybe correct in that respect from the perspective of science and the professions. I suspect Kuhn’s caricature is more true of competitive commercial affairs of business and economies, where his ideas have found wide acceptance in management theories.

Notwithstanding Deutsch’s unifying expanatory power of the four (main) threads, the most powerful message for me – where my original focus was strictly epistemology – models of knowledge – but where I kept tripping up over the undoubted significance of all the other threads – is this.

Causality and free-will have perplexed many a thinker into arriving at the conclusion it’s all an illusion. The fine Sue Blackmore arrived at that very depressing end-point as I noted only a couple of weeks ago, and as did Dan Dennett before her. Well David Deutsch’s explanation is this – analysis leads to to that conclusion only because you believe in the common sensical “flow of time” model in this universe. With the quantum multiverse – all the open futures exist already – what causality does is determine which world which outcome really exists in. Tough to grasp, but convincingly argued.

Not only do free-will and causality exist, thanks to thread (2) but the consequence is immense for thread (4). Even if life turns out to exist only as terrestrial life in this solar system – (an insignificant stain of “scum” on an insignificant planet of an average sun nowhere special in an insignicant galaxy amongst countless others in this universe) – which is itself statistically highly unlikely given the multiverse of universes that exsist in reality – even if that were true – the future of the multiverse depends on the action of our life. Life is the most powerful force determining the future.

That is not just optimistic, it is quite frankly a daunting thought. You can understand the attraction of the pessimistic paradigm – Kuhnian or not.

This is a very important book. Go read.

[A few postscripts – off the main topic …

For you Pisrigians – there’s a nice line in the significance of history in explaining – well – anything, which should add fuel to the philosophy vs philosophology debate.

For those of you “pro-anti-qualia-ists”, “immediate-experiencists”, “what’s-it-like-to-be-a-bat-ists”, “brain-in-a-vat-ists”, or “mary-the-colour-scientists” – there’s an intersting treatise on universal virtual reality generators.

For you sci-fi fans, of which I’m not one, there is a nice angle on explaining so-called time-travel paradoxes.

For you quantum-computists – there is a surprising lack of holography, given the fundamental explanatory nature of quantum interference between the multiple-universes.

For you quantum-consciousness people – there is an sceptical view of large scale coherence (tubules or pixie-dust) supporting anything other than a classical computer in the brain-mind debate.

And many more goodies …. ]

Also published on Medium.

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