Alan Turing: the Unknown Mind
Sezin Gizem Yaman
Helsinki 17 February 2016
UNIVERSITY OF HELSINKI
Department of Computer Science
CONTENT
1) Boyhood
2) The Logical and The Physical
3) Enigma
4) From Turing Test to Artificial Intelligence
5) Unfinished Work
6) Alan Turing: the Unknown Mind
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References
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1) Boyhood
Alan Turing was born in 1912 to an upper-middle-class British parents. Although his
parents were in India initially, they moved to England so that he would born to a more
opportunistic world. His father is known to be occupied with fly fishing with no connection to
the science or academia, whereas mother comes from a family with an engineering base. His
proneness to the science and nature might have inherited from the mother side. Even in the early
childhood he was showing the signs of intelligence. He developed the ability to read and write by
himself. He was good with numbers and puzzles [Hod16].
When he was 14 in order to make it to the first day of the school, he pedaled 200 km
[Alan16]. This school was one of the milestones that changed Turing’s life irrevocably. He met
Christopher Marcom there, his first love who gave a vital period of intellectual companionship.
When Christopher died from tuberculosis, he lost his belief in god. From his letters to Marcom’s
mother it seems that he started to question human mind. He started to think that everything
happening in and around humanbeings have an organic reason [Hod16].
His interest in natural science and mathematics rather than applied sciences has actually
caused him to have lower grades that prevent him from being accepted to his dream universityTrinity College. Instead, he was accepted by King’s College in Cambridge [Ege16]. During his
undergraduate years, he continued to wonder and question about mind and matter. He read
Neumann’s work on logical foundations of quantum mechanics which helped him move towards
rigorous intellectual inquiry from emotions when he was only 20. At the same time, his
homosexuality has become a definitive part of this identity. He was also known with his
association with the anti-war movement and to be closer to the liberal-left economists’ ideologies
[Hod16]. He graduated as a high honor student in 1934. He was admitted for fellowship by
King’s College when he was 22 and given Smith’s Prize the following year for his work on
“probability theory” [Hod16]. By the time he was already very much engaged with pure
mathematics, but his uniqueness in mind was going to drag him to other directions in science that
nobody would have seen at the time.
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Alan Turing [AlanT16]
2) The logical and the Physical
In 1900, famous German mathematician David Hilbert posed the challenge
Entscheidungsproblem, decision problem in English: asking for an algorithm that takes as input a
statement of a first-order logic (possibly with a finite number of axioms beyond the usual axioms
of first-order logic) and answers "Yes" or "No" according to whether the statement is universally
valid, i.e., valid in every structure satisfying the axioms [Ent16].
In 1935, while Turing was taking courses of topologist M. H. A. Newman, he heard about
Entscheidungsproblem which still lay open. He worked on this subject on his own for a year
long. In 1936-7, on his legendary article “on computable numbers”, Alan Turing showed that a
general solution to the Entscheidungsproblem is impossible. By also reviewing Kurt Gödel’s
proof and computation, he designed developed the concept of Turing Machine [Ege16]. He
defined the concept of “mechanical” in terms of atomic operations. With Turing Machine’s
computable functions, notion of effectively calculable is captured. In other words, he stated that
the scope of such a machine is sufficient to encompass everything that has a definite method,
which is nowadays known as “algorithm”.
Here the word “machine” can be misleading, because when he proposed Turing Machine,
there did not exist a physical mechanism yet. It was all theoretical. This abstract machine takes
the postulation that there is an unlimited tape and a reader that can read the symbols on it
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[Hod16]. Through simple instructions as forwards, erase, write, and read, the machine can
manipulate a define method, which is the same principle as how today’s processors work. This
abstraction lay in the foundations of modern computer processers and also led him to move to
Princeton for his doctoral studies later in the same year 1936. It should be also noted here that
Alonso Church had published an independent paper on Entscheidungsproblem almost at the
same time as Turing. Turing had to refer to Church’s work in his paper, which caused some
delay in publishing. Church’s approach to the problem was based on lambda calculus, whereas
Turing’s approach was more expressive and understandable. Due to this reason, his approach
took a wider attention in the science community, including Alonso Church himself, who will be
working with Turing in Princeton from 1936 to 1938 [Hod16].
Turing machine has also pioneered the concept of universal Turing Machine during
around 1940’s. If the concept of Turing Machine is considered like a “formula”, there is
infinitely many Turing Machines corresponding to a different “algorithm”. Universal Turing
Machine is a Turing Machine (formula) that can simulate an arbitrary Turing machine on
arbitrary input [Tur16], [Uni16]. Universal Turing Machine can be seen as a machine for all
possible tasks. Also, Turing’s insight about the symbols representing instructions to do certain
tasks are no different than symbols as numbers used to store information in computers. However,
at the time Turing has imagined these concepts, there was no electronic computer having this
logic turned into engineering. He again managed to link his ideas in his one of the highest level
motivations: that the Universal Turing Machine would exhibit the faculties of human mind and
he dreamed of building a brain.
At Princeton, he worked on “ordinal logics”, probably his deepest work and Ph.D. thesis,
which constitutes the basis of recursion, but he never pursued this line of work after 1938.
During this period, Turing was also going to improve himself in the field of cryptology [Hod16].
3) Enigma
Turing was offered a post at Princeton by von Neumann but instead he was back to
Cambridge shortly after he completed his doctorate in at the end of the year 1938. Unusually for
a mathematician, he attended to lectures of Ludwig Wittgenstein, who was a famous
mathematician and philosopher, on the philosophy and foundations of mathematics. Secretly, he
worked at British Cryptanalytic Department as part-time for a while. Shortly after British
declaration of war, he was invited work in Bletchley Park, war-time Cryptanalytic Headquarters
as full-time. First, he improved the device called Bombey which was able to break Enigma
messages where a small portion of a plain text could be guessed correctly. In the meantime,
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German signals were made more complex and were known to be unbreakable. Turing cracked
the system in 1939. He contributed to the allies’ victory, as he played a big role in decoding axis’
secret information especially regarding German Naval communications [Hod16].
3) From Turing Test to Artificial Intelligence
After WW2, from 1945 to 1948 he worked in National Physical Laboratory. After 1948
he got a fellowship at Manchester University to be the Deputy Director of the computing
laboratory where he worked on his plans to create an electronic computer. Turing at Manchester
have led the world in software development.
It was 1950 when he wrote his famous Artificial Intelligence (AI) article “Computing
Machinery and Intelligence” which was appeared in the philosophical journal “Mind”. In this
article, he discussed on potential problems in AI and possibility that one day machines can think
like humans. As a solution to that, he proposed the test which would ideally differ machines from
humanbeings. According to the design, humanbeing and the machine must stay in different
locations and communicate to each other via a screen and keyboard where they chat. As a result
of the conversation, if humanbeing concludes that he is talking to another humanbeing, that the
machine has the ability to “think” [Hod16].
“The imitation game” comes from his proposal on replacing human thought or
intelligence with imitation. He digs into the philosophy of though and intelligence and questions
what makes a humanbeing (or something) capable of those. So to say, being intelligent is to act
like a human in a convincing and interesting way rather than to have a mind operating like
humans. Again, he implies that rather than the outcome showing that a humanbeing (or
something) is intelligent, the process itself which has effects on the experience is appealing. An
interesting point here is that he never claimed that machines should be as intelligent as
humanbeing nor should stay artificial. Instead, he believed that it will be interesting to see how
computers will perform the imitation game [Bog16].
Captcha, which is being used in the many website nowadays to distinguish between
machines and human beings directly comes from the concept of Turing Test [Alan16].
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Computing Machinery and Intelligence in the Journal “Mind”, 1950 [Com16]
4) Unfinished Work
He thought of utilizing the knowledge and experience he gained during the time he
worked at Bletchley Park together with his strong background in logic, cryptology and some
practical electronic knowledge, in order to establish a real computer. However his ambition and
plans were overshadowed by the by the powerfully supported American projects. Also, due the
secrecy of the work-times at Bletchley Park, he was disadvantaged that it was not allowed for
him to develop further even his own inventions [Ala16]. Frustrated in his work, he run more
often. He actually became a powerful marathon runner, he would have been qualified for the
British team for Olympics if he had more time.
In his last years, from 1952 to 1954, Turing has returned to his initial motivation once
more: his interest in human though and brain and he worked on mathematical biology. He
developed the reaction-diffusion model. In particular, he investigated Fibonacci numbers seen in
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the nature, i.e. plants [Rea16]. In his article published in 1952, the Chemical Basis of
Morphogenesis, he reports on homogenous and uniform distribution of patterns in the nature
[Cab16].
5) Alan Turing: the Unknown Mind
Alan Turing was truly a polymath, not just a computer scientist, but a philosopher, as
well. He was the eccentric guy, who wears a gas mask while biking to protect himself from his
allergies; he was locking his coffee mug to the radiator pipes so that it is not stolen; he was
halting in his speech; known to be nail-bitten and when he was bored he was going out for a 40
km running and coming back to work for even longer shifts. Rowing and sailing were also
known to be his relaxations [Hod16]. He was famous with his sense of humour. He was original.
His work in cryptology, e.g., decoding enigma machines’ signals, is not just an invention
but it also contributes to twentieth century warfare and politics. He developed the theory of
universal computation and the architectural design that is perceived as foundations of modern
computers. He had optimistically foreseen that latest by 2000’s machines would pass the Turing
test. He did not just contributed to the foundations of AI, but also the philosophy of mind.
None of those words were spoken in his own lifetime though. Alan Turing is one of the
most English things that is not being exaggerated. From Beatles to David Beckham, we hear a lot
of names but unfortunately him. The movie called Enigma, which was filmed in 2001 with
Douglas Score and Kate Winslet acting, has no mentioned on Alan Turing although the story is
about the same Enigma machine was decoded by British Secret Services. Most of his work
remained unknown.
He was arrested in and came to trial in 1952 with the claim that he had a sexual affair
with a young Manchester man. He bravely defended himself telling everyone that there was
nothing wrong with his behavior. He has chosen to be injected oestrogen which will diminish his
libido, instead of going to prison for a year. With this, he was disqualified from continuing his
secret cryptological work [Ala16].
On 8 June 1954, he was found by his cleaner, a day after he had bitten a cyanide apple.
Coroner’s verdict was suicide. His mother believed that he accidentally spread cyanide on apply
while he was experimenting. As Turing being one of the greatest minds of all times, he might
have wanted to give a reason to his mom for not believing that her son had committed suicide.
On the other hand, ingesting a cyanide poisoned apple can be seen as an act which simulates his
favorite scene from Snow White. Not just that, but also, he might have wanted to give a message
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to the unfair society justice, as well. His prosecution for homosexuality has shown a huge
problem about the barriers of the society and equity.
Since from the early childhood, he always had the ambition to combine what is logical
and theoretical with the human though and mind. Turing has always intended to make, and he
actually did, a bridge between the logical and physical world and thought and action. This was
behind his motivation for many great works. His name and contributions were not much spoken
at the name, but hopefully his outstanding legacy will be respected more as the time goes by.
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References
[Ala16]
Alan Turing, Stanford Encyclopedia of Philosophy,
http://plato.stanford.edu/entries/turing, [Online; accessed 13-February-2016]
[Alan16]
Alan Turing, https://eksisozluk.com/entry/48660252, [Online; accessed 01February-2016]
[AlanT16]
2016]
Alan Turing, http://totallyhistory.com/alan-turing, [Online; accessed 15-February-
[Bog16]
Bogost, I., The Great Pretender: Turing as a Philosopher of Imitation,
http://www.theatlantic.com/technology/archive/2012/07/the-great-pretender-turing-as-aphilosopher-of-imitation/259824, [Online; accessed 14-February-2016]
[Cab16]
Cable, W., K., Alan Turing’s Reaction-Diffusion Model – Simplification of the
Complex, https://phylogenous.wordpress.com/2010/12/01/alan-turings-reaction-diffusion-modelsimplification-of-the-complex, [Online; accessed 10-February-2016]
[Com16]
Computing machinery and Intelligence,
http://www.atticusrarebooks.com/pages/books/522/alan-mathison-turing/computing-machineryand-intelligence-in-mind-59-1950-pp-433-60, [Online; accessed 15-February-2016]
[Ege16]
Ege, B., Alan Turing, https://eksisozluk.com/entry/39041855, [Online; accessed
01-February-2016]
[Ent16]
Entscheidungsproblem, Wikipedia,
https://en.wikipedia.org/wiki/Entscheidungsproblem, [Online; accessed 10-February-2016]
[Hod16]
Hodges, A., Alan Turing — a short biography,
http://www.turing.org.uk/publications/dnb.html, [Online; accessed 13-February-2016]
[Rea16]
Reaction–diffusion system, Wikipedia
https://en.wikipedia.org/wiki/Reaction%E2%80%93diffusion_system, [Online; accessed 10February-2016]
[Tur16]
Turing Machine, https://en.wikipedia.org/wiki/Turing_machine, [Online; accessed
15-February-2016]
[Uni16]
Universal Turing Machine,
https://en.wikipedia.org/wiki/Universal_Turing_machine, [Online; accessed 15-February-2016]
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