Tuesday, 23 July 2013

Mind and Mechanism – Buddhism and the Turing Machine

Alan Turing
Alan Turing in a letter to Mrs Morcom

Turing’s quest for the spirit

Heartbroken by the untimely death of his boyfriend Christopher Morcom, the young Alan Turing set out to investigate the distinction between the material mechanism of the body and the spirit or mind.        

Christopher died in February of 1930 of bovine tuberculosis, an illness which he had contracted years earlier from tainted milk. Deeply affected by the loss, Alan became obsessed with unravelling the nature of consciousness, its structure and its origins. As his conversations with Mrs. Morcom reveal, he longed to understand what had become of Christopher, of that essential aspect of him: mind.     

Christopher Morcom

Alan Turing’s investigations of the distinction between the discarded mechanism of the body, and the spirit or mind which is reborn after finding a new body 'sooner or later' (within forty-nine  days, according to traditional Buddhist belief) led him to formulate a simple, logically complete and philosophically coherent definition of ‘mechanism’.  

That simple archetypal ‘mechanism’, which can completely simulate the behavior of all other mechanisms and physical systems - including all computers, no matter how complicated - is known as the Turing Machine.

Because of its simplicity, the Turing Machine demonstrates the fundamental capabilities and limitations of all physical systems in a clearly recognisable form.  Turing's machine enables philosophers to develop a clear demarcation between 'mechanism' and 'spirit'.

"If the mind is not the brain..."

Significance of the Turing Machine for Buddhism

The most significant intellectual challenge to Buddhism in the modern world is ‘Materialism’: the belief that the mind is nothing but a product of matter, so that when the mechanism of the body ceases to exist, so does the mind.   There are of course other challenges to Buddhism in the modern world, such as evangelical Christianity and jihadism, but they can hardly be classed as intellectual!

Buddhism is founded upon the Four Seals of Dharma, four philosophical statements of which the fourth states that the mind is non-physical and can transcend biological existence. Obviously materialism contradicts this foundation of Buddhist belief. 

As described elsewhere, it is surprisingly difficult to get a definition of materialism based on the concept of matter, because it is difficult to get a coherent definition of matter as a ‘thing in itself’, totally disentangled from the mind of the observer.  For this reason, the philosophical view formerly known as ‘Materialism’, or ‘Physicalism’ (or even more archaically as ‘Naturalism’) is nowadays expressed as the Computational Theory of Mind, otherwise known as ‘Computationalism’.

The Computational Theory of Mind grew up in the 1950’s, when computers were being hyped as ‘Electronic Brains’ and their potentials were seen as limitless, including the ability to simulate all human mental processes.  However, the computational theory was soon found to have at least two serious limitations:

(1)  The limitation of Aboutness
The computational theory of mind could not account for ‘aboutness’ (technically known as ‘intentionality’). A computer operates on character strings, whose meaning is inaccessible to a machine. 

The number 11

For example, a computer carries no internal reference to what the character string ‘elf’ is about. It could refer to the number eleven in German, or one of Santa’s helpers in English, but the computer neither knows nor cares, and has no mechanism for knowing or caring.

Readers familiar with high level programming languages such as FORTRAN or BASIC may protest that the variable names used in their program statements do have meaning. This is true only in so far as they have meaning for the programmer, but they have no meaning for the machine.  For example, the statements used to describe the requirements for carpet laying and the theatrical success of a musical comedy about Hitler seem to have very different meanings...



But both statements have all their meaning stripped out during compilation into the binary strings that can be used by computers, and end up as exactly the same logical and arithmetic operations on the same anonymous memory locations.  This is the fundamental difference between a mind actively cognising and a machine passively representing an object.

(2)  The limitation of Qualitative Experience.
Computers can only process logical, structural and numeric quantities.  They can neither experience nor react to internal qualitative mental states such as pleasure or pain, nor experience the redness of red or the smell of flowers (though they can record the wavelength of light and molecular structures of scents)

The reasons why these limitations are fundamental, and indeed fatal, to computationalism (and hence materialism) becomes apparent once we examine the structure of the Turing machine in the light of Buddhist philosophical theory and meditational practice, but first we need to understand the working of the Turing machine in greater detail. Fortunately there are only four components:

So what is a Turing Machine?

A Turing machine consists of just two main components: 

There are also two minor components:

The tape consists of a string of characters. These are sometimes imprecisely described as 'symbols', but this is rather confusing in that symbols often make reference to something beyond themselves (they exhibit 'derived intentionality' or evoke a qualitative state of mind.)   It is important to remember that the characters on the tape, like the string ‘elf’,  carry no intrinsic meaning.   


4   The new character to be written to the tape.


In accordance with the three remaining columns in that row, t
he machine then:

(i) changes the state of the register
(ii) moves the head  
(iii) writes a new character on the tape 


- Computer equivalence of the Turing Machine
completely functionally  equivalent to any real-world computer.


- Physical equivalence of the Turing Machine



So Alan Turing had well and truly defined ‘mechanism’, including biophysical mechanisms such as the body.  We now turn our attention to the ‘spirit’ or mind.

- Mind equivalence of the Turing Machine?

- - Inability of the Turing machine to emulate mental designation

Causes  - which correspond to the table
Structure - which corresponds to the tape


- - Inability of the Turing Machine to hold and manipulate qualitative states.


The inability to formulate any mechanical procedure to generate qualia was first described by the eminent Victorian physicist John Tyndall over 140 years ago:


What Tyndall is basically saying, behind the rather flowery Victorian language, is an early recognition of the Hard Problem: that there is no logically describable physical mechanism that can get from quantitative physical inputs to qualitative experience.

So in following the Lamrim meditations, the mind is doing something that no machine could ever do.  



The behavior of the mind shows at least two functions - aboutness  and qualitative experience - that cannot in principle be reduced to the operations of a Turing machine.


- Sean Robsville

Read more at Buddhist Philosophy


Crude said...

Interesting post, but I don't have much comment on it. The problem is, that last picture's text is not only extraordinarily deceptive - it's basically a lie.

First, it implies that Turing was sentenced for being homosexual. He wasn't. He was sentenced after it was found that he engaged in sodomy with a teenage homeless man he picked up and who ended up robbing his house, and when Turing tried to press charges, the relationship was found out. 'Homosexuality' was not illegal in the UK, unless someone identifies homosexuality with sodomy - in which case, there's quite a lot of straight homosexuals out there.

Second, it implies that Turing killed himself under the duress of being faced with those penalties. In reality, Turing chose chemical castration - and then lived on for another year before he died. He was not viewed as being distraught over this, even until he died.

Third, it implies that Turing committed suicide. To say this is disputed is to put it mildly. People who speculate about him having committed suicide come up with the story that the reason Turing's death didn't even look like a suicide was because he was trying to make it look like an accident for his mother's sake. That is some wild speculation to say the least.

Fourth, part of the reason Turing's sexual antics were a concern was because they could have opened him up to blackmail - something we've seen recently with Petraeus.

Saying the law was wrong is one thing, but the Turing case is simply not what people tend to present it as being - and that picture is particularly nasty about it.

r3lf said...

Turing Machines are too simple. Maybe Paraconsistent / Paracomplete Turing machines (PTM).
Paraconsitent Turing Machines use a paraconsistent logic, i.e. FDE (First Degree Entailment)
First Degree Entailment was developed to work on databases that were fed with incomplete or contradictory informations.
Translated to the Buddhist teachings, which are a constructivistic approach, this would mean the illusionary nature of realitiy (incomplete / contradictory information)
There are several approaches that that link PTMs and quantum computing and that is the point.

One could say that the material world is generated in the (collective) subconsciousness, while our waking consciousness is a filtered version of this collective subconsciousness.

At the end of the collective subconsciousness is the 'void state' or 'white light state' that represents total symmetry.

There are more facts one has to take in account, but mankind is very far away from building artificial life, meaning life not based on DNA / RNA.