Quotes from work
Computing Machinery and Intelligence

Alan Turing

"Computing Machinery and Intelligence" is a seminal paper written by Alan Turing on the topic of artificial intelligence. The paper, published in 1950 in Mind, was the first to introduce his concept of what is now known as the Turing test to the general public.

“The view that machines cannot give rise to surprises is due, I believe, to a fallacy to which philosophers and mathematicians are particularly subject. This is the assumption that as soon as a fact is presented to a mind all consequences of that fact spring into the mind simultaneously with it. It is a very useful assumption under many circumstances, but one too easily forgets that it is false.”

Alan Turing Computing Machinery and Intelligence

Source: Computing Machinery and Intelligence (1950), p. 451.
Context: The view that machines cannot give rise to surprises is due, I believe, to a fallacy to which philosophers and mathematicians are particularly subject. This is the assumption that as soon as a fact is presented to a mind all consequences of that fact spring into the mind simultaneously with it. It is a very useful assumption under many circumstances, but one too easily forgets that it is false. A natural consequence of doing so is that one then assumes that there is no virtue in the mere working out of consequences from data and general principles.

“Machines take me by surprise with great frequency.”

Alan Turing Computing Machinery and Intelligence

Source: Computing Machinery and Intelligence (1950), p. 450.

“The majority of them seem to be "sub-critical," i.e., to correspond in this analogy to piles of sub-critical size. An idea presented to such a mind will on average give rise to less than one idea in reply. A smallish proportion are super-critical. An idea presented to such a mind may give rise to a whole "theory" consisting of secondary, tertiary and more remote ideas.”

Alan Turing Computing Machinery and Intelligence

Source: Computing Machinery and Intelligence (1950), p. 454.
Context: Another simile would be an atomic pile of less than critical size: an injected idea is to correspond to a neutron entering the pile from without. Each such neutron will cause a certain disturbance which eventually dies away. If, however, the size of the pile is sufficiently increased, the disturbance caused by such an incoming neutron will very likely go on and on increasing until the whole pile is destroyed. Is there a corresponding phenomenon for minds, and is there one for machines? There does seem to be one for the human mind. The majority of them seem to be "sub-critical," i. e., to correspond in this analogy to piles of sub-critical size. An idea presented to such a mind will on average give rise to less than one idea in reply. A smallish proportion are super-critical. An idea presented to such a mind may give rise to a whole "theory" consisting of secondary, tertiary and more remote ideas. Animals minds seem to be very definitely sub-critical. Adhering to this analogy we ask, "Can a machine be made to be super-critical?"

“I am not very impressed with theological arguments whatever they may be used to support. Such arguments have often been found unsatisfactory in the past.”

Alan Turing Computing Machinery and Intelligence

Source: Computing Machinery and Intelligence (1950), pp. 443-444.
Context: I am not very impressed with theological arguments whatever they may be used to support. Such arguments have often been found unsatisfactory in the past. In the time of Galileo it was argued that the texts, "And the sun stood still... and hasted not to go down about a whole day" (Joshua x. 13) and "He laid the foundations of the earth, that it should not move at any time" (Psalm cv. 5) were an adequate refutation of the Copernican theory.

“Presumably the child-brain is something like a note-book as one buys it from the stationer's. Rather little mechanism, and lots of blank sheets.”

Alan Turing Computing Machinery and Intelligence

Source: Computing Machinery and Intelligence (1950), p. 456.

“May not machines carry out something which ought to be described as thinking but which is very different from what a man does?”

Alan Turing Computing Machinery and Intelligence

Computing Machinery and Intelligence (1950)

“Suppose Mother wants Tommy to call at the cobbler's every morning on his way to school to see if her shoes are done, she can ask him afresh every morning. Alternatively she can stick up a notice once and for all in the hall which he will see when he leaves for school and which tells him to call for the shoes, and also to destroy the notice when he comes back if he has the shoes with him.”

Alan Turing Computing Machinery and Intelligence

Computing Machinery and Intelligence (1950)

“We are not asking whether all digital computers would do well in the game nor whether the computers at present available would do well, but whether there are imaginable computers which would do well.”

Alan Turing Computing Machinery and Intelligence

Computing Machinery and Intelligence (1950)

“A digital computer can usually be regarded as consisting of three parts: (i) Store. (ii) Executive unit. (iii) Control…. The executive unit is the part which carries out the various individual operations involved in a calculation…. It is the duty of the control to see that… [the table of] instructions are obeyed correctly and in the right order…. A typical instruction might say—"Add the number stored in position 6809 to that in 4302 and put the result back into the latter storage position." Needless to say it would not occur in the machine expressed in English. It would more likely be coded in a form such as 6809430217. Here 17 says which of various possible operations [add] is to be performed on the two numbers…. It will be noticed that the instruction takes up 10 digits and so forms one packet of information…”

Alan Turing Computing Machinery and Intelligence

Computing Machinery and Intelligence (1950)

“We can only see a short distance ahead, but we can see plenty there that needs to be done.”

Alan Turing Computing Machinery and Intelligence

Source: Computing Machinery and Intelligence (1950), p. 460.
Source: Computing machinery and intelligence

“These questions replace our original, "Can machines think?"”

Alan Turing Computing Machinery and Intelligence

Computing Machinery and Intelligence (1950)
Context: "Can machines think?"... The new form of the problem can be described in terms of a game which we call the 'imitation game." It is played with three people, a man (A), a woman (B), and an interrogator (C) who may be of either sex. The interrogator stays in a room apart front the other two. The object of the game for the interrogator is to determine which of the other two is the man and which is the woman. He knows them by labels X and Y, and at the end of the game he says either "X is A and Y is B" or "X is B and Y is A." The interrogator is allowed to put questions to A and B... We now ask the question, "What will happen when a machine takes the part of A in this game?" Will the interrogator decide wrongly as often when the game is played like this as he does when the game is played between a man and a woman? These questions replace our original, "Can machines think?"

“I believe that at the end of the century the use of words and general educated opinion will have altered so much that one will be able to speak of machines thinking without expecting to be contradicted.”

Alan Turing Computing Machinery and Intelligence

Source: Computing Machinery and Intelligence (1950), p. 442.
Source: Computing machinery and intelligence

“If one wants to make a machine mimic the behaviour of the human computer in some complex operation one has to ask him how it is done, and then translate the answer into the form of an instruction table. Constructing instruction tables is usually described as "programming."”

Alan Turing Computing Machinery and Intelligence

Computing Machinery and Intelligence (1950)

“The idea behind digital computers may be explained by saying that these machines are intended to carry out any operations which could be done by a human computer.”

Alan Turing Computing Machinery and Intelligence

Source: Computing Machinery and Intelligence (1950), p. 436.

“We do not wish to penalise the machine for its inability to shine in beauty competitions, nor to penalise a man for losing in a race against an aeroplane. The conditions of our game make these disabilities irrelevant.”

Alan Turing Computing Machinery and Intelligence

Computing Machinery and Intelligence (1950)