Kategori: Philosophy of mind

Reading Notes I: Tegmark and substrate independence

Perscrutor

Tegmark (2017:67) writes “This substrate independence of computation implies that AI is possible: intelligence doesn’t require flesh, blood or carbon atoms.”. How should we read this? The background is that he argues that computation is independent of what we use for hardware and software and what is required is only that the matter we compute in fulfills som very simple conditions like sufficient stability (what would intelligence look like if it was based on gases rather than more solid matter, one could ask – remembering the gas giants in Bank’s novels, by the way – sufficiently large gases may be stable enough to support computation?). But what is more interesting here is the quick transition from computation to intelligence. Tegmark does not violate any of his own assumptions here – he is exceptionally clear about what he thinks intelligence is and builds on a Simonesque notion of attaining goals – but there still seems to be a lot of questions that could be asked about the move from computation to intelligence. The questions that this raises for me are the following:

(i) Is computation the same as intelligence (i.e. is intelligence a kind of computation – and if it is not what is it then?)

(ii) It is true that computation is substrate agnostic, but is not substrate independent. Without any substrate there can be no computing at all, so what does this substrate dependence mean for intelligence? Is it not possible that the nature of the matter used for computation matters for the resultant computation? A very simple example seems to be the idea of computation at different temperatures and what extreme temperatures may lead to (but maybe Tegmark here would argue that this violates the stability condition).

(iii) In a way this seems to be assuming what is to be proven. What Chalmers and others argue is that while computation may be substrate agnostic, cognition or consciousness is not. If there was a way to show that intelligence is substrate specific – only certain classes of matter can be intelligent – what would that look like?

(iv) The question of consciousness is deftly avoided in the quoted sentence, but is there an aspect of observation, consciousness and matter somewhere that seems to matter. I know too little about the role of observation in quantum physics to really nail this down right now, but is it not possible that there exists certain kinds of matter that can observe, and others that cannot?

(v) Even if intelligence is substrate agnostic, as computation, may it not be dependent on certain levels of complexity in the organization of the computation and may it not be the case that these levels of complexity can only be achieved in certain classes of matter? That is, is there an additional criterion for intelligence, in addition to the stability criterion laid out by Tegmark, that needs to be taken into account here?

(vi) What would the world have to be like for intelligence NOT to be substrate agnostic? What would we call the quality that some classes of matter has that others lack and that means that those classes can carry intelligence.

(vii) the close connection between computation and intelligence seems to open itself up to a criticism based on Wittgenstein’s notion of an “attitude to a soul”. Is this just a trite linguistic gripe, or a real concern when we speak about intelligence?

(viii) It seems as if we can detect computation in matter, does this mean that we can detect intelligence just by detecting computation? Clearly not. What is it that we detect when we detect intelligence? This brings us back to the question of tests, of the Turing test et cetera. The Turing test has arguably been passed many times, but is not an interesting test at all – but is there a test for intelligence that can be reduced to a physical measurement? There certainly should be a test for computation that can be easily designed, right?

(ix) Intelligence is a concept that applies to action over a longer time than computation. Does the time factor change the possible equivalence between the concepts?

A lot to think about. Fascinating book so far.

Aspect seeing and consciousness I: What Vampires Cannot Do

Perscrutor

In the novel Blindsight by Peter Watts mankind has resurrected vampires (no, not a good idea) – found in the book to be real predators that became extinct. One difference between vampires and humans is that vampires can see both aspects of a Necker cube at the same time – they are able to do hyper-threading and think several thoughts at the same time. In other words, vampires are capable of seeing two aspects of something – or more – simultaneously.

Wittgenstein studies this phenomenon in the second part of Philosophical Investigations, and one interpretation of his remarks is that he sees aspect seeing as a way to show how language can confound us. When we see only one aspect of something we forget that it can equally be something else, and that this is how we are confused. The duck-rabbit is not either duck or rabbit, it is ultimately both, it can be seen as both animals.

 

But maybe we can learn even more from his discussion of aspect seeing by examining the device Watts uses? The duck-rabbit, the Necker-cube and the old woman/young woman are all interesting examples of how we see one or the other aspect of something. But what would it mean to see both? Let’s assume for the moment that there is a being – a vampire as Watts has it – that can see both aspects at the same time. What would that be like?

Trivially we can imagine _two_ people who look at a Necker cube and see both aspects of it. That is not a hard thing to understand or accept. But a single person seeing both aspects at the same time, that seems more challenging, if not impossible. And maybe this is the thing to explore. What if the following holds true:

(i) Consciousness is limited to a single aspect in the world at a time.

We need to dig further, as this is a very imprecise way to put it, we want to find something more general and distinct to say here. When you are looking at a Necker cube you can only see one aspect at a time, and that is a necessary component of being a “you”. Conscious observation collapses the world to a single aspect out of a multitude of aspects.

That seem trivial. What we are now saying is that in order to see the world, you need to see the world in one specific way at a time. You cannot see it in different ways simultaneously. And that hits on something worth dwelling a bit on – the issue of time in aspect seeing. When you see an aspect of something you construct it in your head over time – it is like having lego pieces and assembling as specific lego construction. Just as you cannot assemble two lego constructions out of the same pieces at the same time you need to limit yourself to one single aspect when several are offered.

This idea, that two simultaneous aspects cannot be constructed out of observation at the same time points to consciousness as “single-threading” rather than “hyper-threading” with Watt’s terminology. But there is no way to imagine a world in which you can make two different simultaneous lego constructions out of lego pieces, that simply is a violation of the way the world is. Now, that opens up the following question:

Q1: Is hyper-threading as described by Watts necessarily impossible in the same way that the simultaneously different lego constructions built from the same pieces are?

This in turn is an interesting question, since it seems to imply that we have a boundary condition for consciousness here – it is necessarily single-threaded, or should be treated as two different consciousnesses in the same body as per our early observation that it is easy to imagine two observers seeing different aspects of the same thing.

We can then develop (i) into:

(ii) Consciousness is necessarily single-threaded.

What would this limitation imply, except that we cannot see a Necker cube in both ways at the same time? It would imply that the necessary reduction of several aspects into a single one is a pre-requisite for us to call something individually conscious.

I suspect there is more here, and want to return to this later, perhaps in a more structured fashion.