Philosophy 1050: Introduction to Philosophy Week 12: “Thinking Machines”: Artificial Intelligence and Human Minds

Mind and Intelligence: Dualism vs. Physicalism ► Last week we considered the debate between the dualism – according to which there is a non-physical “mind” or “soul” connected to the physical brain – and physicalism – according to which there is no non-physical mind and all of our behavior and action can be explained by the physical actions and processes of the brain.

Artificial Intelligence: The Question ► This week, we’ll consider an important related question. Could it ever be possible for a machine – something made by humans – to actually think, reason, hold beliefs, have conscious experiences, etc.? ► And how could we tell if it could?

Blade Runner : (Do Androids Dream of Electric Sheep?) ► The year is 2019 ► Deckard (Harrison Ford) is a “Blade Runner” – an elite cop trained to find and hunt down human-like androids or “replicants” ► Six replicants have escaped from a prison colony and are causing problems

Blade Runner: The Voight-Kampf Test ► In order to tell whether a subject is human or a replicant, investigators use a complex test called the “voight-kampf” test to evaluate their responses and reactions ► Some of the newest generation of replicants have been designed to give emotional responses and have even been implanted with “false memories” so that they themselves do not know they are not human.

Blade Runner ► If you were Deckard and were confronted with a tricky subject who might be a Replicant, what questions would you want to ask him? ► How could you know for sure whether your subject was human or not? Could you know for sure?

Turing and Computers ► Alan Turing ( ) ► During World War II, Turing’s work on code- breaking was instrumental in breaking the “Enigma” code used by the German and Japanese armies ► Because of this Turing has been called the one individual most responsible for winning the war for the allies

Turing and Computers ► Turing’s ideas about language and symbols led him to develop the idea of a “Turing machine” or a universal computing machine ► The basic structure of this machine is used by every computer that exists today

Turing’s Prediction (1950) ► “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 …”

Artificial Intelligence Since Turing ► Since Turing wrote, artificial intelligence has made great strides forward. We now have computers that can identify faces, read music, write poetry, and solve problems that no human could ever solve. ► In 1997, IBM’s Deep Blue defeated the world chess champion, Gary Kasparov, in a match of seven games.

Artificial Intelligence: What are the Bounds? ► Since 1950, tasks once thought possible only for human beings have again and again been accomplished by computers. ► Are there limits to this progress? Is there anything that humans can do that computers or machines never will be able to?

Turing: The “Turing Test” ► Turing considers the question: “Can Computers Think?” ► But this question is unclear and difficult to answer. Turing suggests replacing it with another question, which he puts in the form of an “imitation game” or “test”

The Turing Test ► A judge is connected to two subjects by teletype machine ► One of the subjects is a machine and the other is a person: the judge doesn’t know which is which ► If the machine can fool the judge into believing it is a person, it is actually thinking.

The Turing Test ► “I believe that in about fifty years' time it will be possible to programme computers, with a storage capacity of about 10 9, to make them play the imitation game so well that an average interrogator will not have more than 70 per cent chance of making the right identification after five minutes of questioning.” (p. 4) ► Do we agree with Turing? If a computer can pass the Turing test 70% of the time, is it actually thinking?

The Turing Test: Questions and Objections ► Is there anything essential that a human being can do that a computer could never do? Why? ► Even if a computer can pass a Turing test, how do we know it is really thinking as opposed to imitating or simulating thought? ► If the Turing test is not a good test for actual thinking, is there any better test?

Computer Thinking: Objections 1) The Theological Objection: “Thinking is a function of man’s immortal soul. God has given an immortal soul to every man and woman, but not to any other animal or to machines. Hence no animal or machine can think.” (p. 5) Response: 1) If God can create bodies and attach souls to them, he could also attach souls to computers 2) Theological arguments are unsatisfactory for establishing scientific conclusions

Computer Thinking: Objections 2) The “Heads in the Sand” Objection: “The consequences of machines thinking would be too dreadful. Let’s hope and believe that they cannot do so.” (p. 6) Response: This is not really an argument at all, but just an appeal for consolation.

Computer Thinking: Objections 4) The Argument from Consciousness: “No machine could feel (and not merely artificially signal...) pleasure at its successes, grief when its valves fuse, be warmed by flattery, be made miserable by its mistakes, be charmed by sex, be angry or depressed when it cannot get what it wants.” (Geoffery Jefferson, 1949 (P. 6)) Response: If it is impossible to know that a machine is really conscious judging from its responses, then it is impossible to know whether any other person is really conscious as well. If the Turing test could not show that a computer is really thinking, then it is impossible for me to show that anyone else (other than myself) is really thinking.

Computer Thinking: Objections 5) Arguments from Various Disabilities: No computer could ever do X (where X is, e.g. “Be kind, resourceful, beautiful, friendly, have initiative, have a sense of humour, tell right from wrong, make mistakes, fall in love, enjoy strawberries and cream, make some one fall in love with it, learn from experience, use words properly, be the subject of its own thought, have as much diversity of behaviour as a man, do something really new.” (p. 8) Response: Various, but all of these seem to be based on a bad extrapolation from what we have seen before. Some of the computers we have seen cannot do these things, but that is no reason to think we could not eventually build a computer that can.

Computer Thinking: Objections 6) Lady Lovelace’s Objection: Computers only do what they are programmed to do, so it is impossible for a computer ever to learn something new or do something unexpected Response: Computers do “new” and surprising things all the time. It is also easily possible for us to set up a mechanism whereby a computer can modify its own program, and thereby can be said to have “learned.”

Computer Thinking: Minds and Machines ► “The ‘skin-of-an-onion analogy is also helpful. In considering the functions of the mind or brain we find certain operations which we can explain in purely mechanical terms. This we say does not correspond to the real mind: it is a sort of skin which we must strip off to find the real mind. But then in what remains we find a further skin to be stripped off, and so on. Proceeding in this way do we ever come to the ‘real’ mind, or do we eventually come to the skin which has nothing in it? In the latter case the mind is mechanical.” (Turing, p. 12)

Computer Thinking: Summary ► Turing suggested that computers could think and he suggested the Turing test to determine whether they can think. ► If we accept the test, it will be difficult to hold onto a dualist or theological view of human consciousness ► On the other hand, it is not obvious how to explain consciousness or the possibility of a physical organism giving rise to experience at all