Philosophy of artificial intelligence
Encyclopedia
The philosophy of artificial intelligence
attempts to answer such questions as:
These three questions reflect the divergent interests of AI researchers
, philosopher
s and cognitive scientists
respectively. The answers to these questions depend on how one defines "intelligence" or "consciousness" and exactly which "machines" are under discussion.
Important proposition
s in the philosophy of AI include:
, cognitive scientists and philosophers
; to answer this question, it does not matter whether a machine is really thinking (as a person thinks) or is just acting like it is thinking.
The basic position of most AI researchers is summed up in this statement, which appeared in the proposal for the Dartmouth Conferences of 1956:
Arguments against the basic premise must show that building a working AI system is impossible, because there is some practical limit to the abilities of computers or that there is some special quality of the human mind that is necessary for thinking and yet cannot be duplicated by a machine (or by the methods of current AI research). Arguments in favor of the basic premise must show that such a system is possible.
The first step to answering the question is to clearly define "intelligence."
, in a famous and seminal 1950 paper, reduced the problem of defining intelligence to a simple question about conversation. He suggests that: if a machine can answer any question put to it, using the same words that an ordinary person would, then we may call that machine intelligent. A modern version of his experimental design would use an online chat room
, where one of the participants is a real person and one of the participants is a computer program. The program passes the test if no one can tell which of the two participants is human. Turing notes that no one (except philosophers) ever asks the question "can people think?" He writes "instead of arguing continually over this point, it is usual to have a polite convention that everyone thinks." Turing's test extends this polite convention to machines:
is that it is explicitly anthropomorphic. If our ultimate goal is to create machines that are more intelligent than people, why should we insist that our machines must closely resemble people? Russell
and Norvig
write that "aeronautical engineering texts do not define the goal of their field as 'making machines that fly so exactly like pigeons that they can fool other pigeons.'" Recent AI research defines intelligence in terms of intelligent agent
s. An "agent" is something which perceives and acts in an environment. A "performance measure" defines what counts as success for the agent.
Definitions like this one try to capture the essence of intelligence. They have the advantage that, unlike the Turing test, they do not also test for human traits that we may not want to consider intelligent, like the ability to be insulted or the temptation to lie. They have the disadvantage that they fail to make the commonsense differentiation between "things that think" and "things that do not". By this definition, even a thermostat has a rudimentary intelligence and consciousness.
writes that "if the nervous system obeys the laws of physics and chemistry, which we have every reason to suppose it does, then .... we ... ought to be able to reproduce the behavior of the nervous system with some physical device." This argument, first introduced as early as 1943 and vividly described by Hans Moravec
in 1988, is now associated with futurist Ray Kurzweil, who estimates that computer power will be sufficient for a complete brain simulation by the year 2029. A non-real-time simulation of a thalamocortical model that has the size of the human brain (1011 neurons) was performed in 2005 and it took 50 days to simulate 1 second of brain dynamics on a cluster of 27 processors (see also ).
Few disagree that a brain simulation is possible in theory, even critics of AI such as Hubert Dreyfus
and John Searle.
However, Searle points out that, in principle, anything can be simulated by a computer, and so any process at all can be considered "computation", if you're willing to stretch the definition to the breaking point. "What we wanted to know is what distinguishes the mind from thermostats and livers," he writes. Any argument that involves simply copying a brain is an argument that admits that we know nothing about how intelligence works. "If we had to know how the brain worked to do AI, we wouldn't bother with AI," writes Searle.
and Herbert Simon
proposed that "symbol manipulation" was the essence of both human and machine intelligence. They wrote:
This claim is very strong: it implies both that human thinking is a kind of symbol manipulation (because a symbol system is necessary for intelligence) and that machines can be intelligent (because a symbol system is sufficient for intelligence). Another version of this position was described by philosopher Hubert Dreyfus, who called it "the psychological assumption":
A distinction is usually made between the kind of high level symbols that directly correspond with objects in the world, such as
. Early research into AI, called "good old fashioned artificial intelligence" (GOFAI
) by John Haugeland
, focused on these kind of high level symbols.
In 1931, Kurt Gödel
proved that it is always possible to create statement
s that a formal system
(such as a high-level symbol manipulation program) could not prove. A human being, however, can (with some thought) see the truth of these "Gödel statements". This proved to philosopher John Lucas
that human reason would always be superior to machines. He wrote "Gödel's theorem seems to me to prove that mechanism is false, that is, that minds cannot be explained as machines."
Roger Penrose
expanded on this argument in his 1989 book The Emperor's New Mind
, where he speculated that quantum mechanical processes inside individual neurons gave humans this special advantage over machines.
Douglas Hofstadter
, in his Pulitzer prize
winning book Gödel, Escher, Bach: An Eternal Golden Braid, explains that these "Gödel-statements" always refer to the system itself, similar to the way the Epimenides paradox
uses statements that refer to themselves, such as "this statement is false" or "I am lying". But, of course, the Epimenides paradox
applies to anything that makes statements, whether they are machines or humans, even Lucas himself. Consider:
This statement is true but cannot be asserted by Lucas. This shows that Lucas himself is subject to the same limits that he describes for machines, as are all people, and so Lucas
's argument is pointless.
Further, Russell and Norvig note that Gödel's argument only applies to what can theoretically be proved, given an infinite amount of memory and time. In practice, real machines (including humans) have finite resources and will have difficulty proving many theorems. It is not necessary to prove everything in order to be intelligent.
Hubert Dreyfus argued that human intelligence and expertise depended primarily on unconscious instincts rather than conscious symbolic manipulation, and argued that these unconscious skills would never be captured in formal rules.
Dreyfus
's argument had been anticipated by Turing in his 1950 paper Computing machinery and intelligence
, where he had classified this as the "argument from the informality of behavior." Turing argued in response that, just because we do not know the rules that govern a complex behavior, this does not mean that no such rules exist. He wrote: "we cannot so easily convince ourselves of the absence of complete laws of behaviour ... The only way we know of for finding such laws is scientific observation, and we certainly know of no circumstances under which we could say, 'We have searched enough. There are no such laws.'"
Russell and Norvig
point out that, in the years since Dreyfus published his critique, progress has been made towards discovering the "rules" that govern unconscious reasoning. The situated
movement in robotics
research attempts to capture our unconscious skills at perception and attention. Computational intelligence
paradigms, such as neural nets, evolutionary algorithm
s and so on are mostly directed at simulated unconscious reasoning and learning. Research into commonsense knowledge has focused on reproducing the "background" or context of knowledge. In fact, AI research in general has moved away from high level symbol manipulation or "GOFAI
", towards new models that are intended to capture more of our unconscious reasoning. Historian and AI researcher Daniel Crevier
wrote that "time has proven the accuracy and perceptiveness of some of Dreyfus's comments. Had he formulated them less aggressively, constructive actions they suggested might have been taken much earlier."
and the hard problem of consciousness
. The question revolves around a position defined by John Searle as "strong AI":
Searle distinguished this position from what he called "weak AI":
Searle introduced the terms to isolate strong AI from weak AI so he could focus on what he thought was the more interesting and debatable issue. He argued that even if we assume that we had a computer program that acted exactly like a human mind, there would still be a difficult philosophical question that needed to be answered.
Neither of Searle's two positions are of great concern to AI research, since they do not directly answer the question "can a machine display general intelligence?" (unless it can also be shown that consciousness is necessary for intelligence). There are a few researchers who believe that consciousness is an essential element in intelligence, such as Igor Aleksander
, Stan Franklin
, Ron Sun
, and Pentti Haikonen, although their definition of "consciousness" strays very close to "intelligence." See artificial consciousness
. Turing wrote "I do not wish to give the impression that I think there is no mystery about consciousness ... [b]ut I do not think these mysteries necessarily need to be solved before we can answer the question [of whether machines can think]." Russell
and Norvig agree: "Most AI researchers take the weak AI hypothesis for granted, and don't care about the strong AI hypothesis."
Before we can answer this question, we must be clear what we mean by "minds", "mental states" and "consciousness".
" and "consciousness
" are used by different communities in different ways. Some new age
thinkers, for example, use the word "consciousness" to describe something similar to Bergson's "élan vital
": an invisible, energetic fluid that permeates life and especially the mind. Science fiction
writers use the word to describe some essential
property that makes us human: a machine or alien that is "conscious" will be presented as a fully human character, with intelligence, desires, will, insight, pride and so on. (Science fiction writers also use the words "sentience", "sapience," "self-awareness" or "ghost" (as in the Ghost in the Shell
manga and anime series) to describe this essential human property.) For others, the words "mind" or "consciousness" are used as a kind of secular synonym for the soul
.
For philosophers
, neuroscientists
and cognitive scientists, the words are used in a way that is both more precise and more mundane: they refer to the familiar, everyday experience of having a "thought in your head", like a perception, a dream, an intention or a plan, and to the way we know something, or mean something or understand something. "It's not hard to give a commonsense definition of consciousness" observes philosopher John Searle. What is mysterious and fascinating is not so much what it is but how it is: how does a lump of fatty tissue and electricity give rise to this (familiar) experience of perceiving, meaning or thinking?
Philosophers call this the hard problem of consciousness
. It is the latest version of a classic problem in the philosophy of mind
called the "mind-body problem." A related problem is the problem of meaning or understanding (which philosophers call "intentionality
"): what is the connection between our thoughts and what we are thinking about (i.e. objects and situations out in the world)? A third issue is the problem of experience (or "phenomenology"): If two people see the same thing, do they have the same experience? Or are there things "inside their head" (called "qualia
") that can be different from person to person?
Neurobiologists believe all these problems will be solved as we begin to identify the neural correlates of consciousness
: the actual relationship between the machinery in our heads and its collective properties; such as the mind, experience and understanding. Some of the harshest critics of artificial intelligence
agree that the brain is just a machine, and that consciousness and intelligence are the result of physical processes in the brain. The difficult philosophical question is this: can a computer program, running on a digital machine that shuffles the binary digits of zero and one, duplicate the ability of the neurons
to create minds, with mental state
s (like understanding or perceiving), and ultimately, the experience of consciousness
?
: suppose we have written a computer program that passes the Turing Test and demonstrates "general intelligent action." Suppose, specifically that the program can converse in fluent Chinese. Write the program on 3x5 cards and give them to an ordinary person who does not speak Chinese. Lock the person into a room and have him follow the instructions on the cards. He will copy out Chinese characters and pass them in and out of the room through a slot. From the outside, it will appear that the Chinese room contains a fully intelligent person who speaks Chinese. The question is this: is there anyone (or anything) in the room that understands Chinese? That is, is there anything that has the mental state
of understanding
, or which has conscious
awareness
of what is being discussed in Chinese? The man is clearly not aware. The room cannot be aware. The cards certainly aren't aware. Searle concludes that the Chinese room
, or any other physical symbol system, cannot have a mind.
Searle goes on to argue that actual mental state
s and consciousness
require (yet to be described) "actual physical-chemical properties of actual human brains." He argues there are special "causal properties" of brain
s and neuron
s that gives rise to mind
s: in his words "brains cause minds."
made essentially the same argument as Searle in 1714, using the thought experiment of expanding the brain until it was the size of a mill. In 1974, Lawrence Davis imagined duplicating the brain using telephone lines and offices staffed by people, and in 1978 Ned Block envisioned the entire population of China involved in such a brain simulation. This thought experiment is called "the Chinese Nation" or "the Chinese Gym". Ned Block also proposed his "blockhead" argument, which is a version of the Chinese room
in which the program has been re-factored into a simple set of rules of the form "see this, do that", removing all mystery from the program.
, who study the nature of human thinking and problem solving.
The computational theory of mind
or "computationalism" claims that the relationship between mind and brain is similar (if not identical) to the relationship between a running program and a computer. The idea has philosophical roots in Hobbes (who claimed reasoning was "nothing more than reckoning"), Leibniz (who attempted to create a logical calculus of all human ideas), Hume
(who thought perception could be reduced to "atomic impressions") and even Kant
(who analyzed all experience as controlled by formal rules). The latest version is associated with philosophers Hilary Putnam
and Jerry Fodor
.
This question bears on our earlier questions: if the human brain is a kind of computer then computers can be both intelligent and conscious, answering both the practical and philosophical questions of AI. In terms of the practical question of AI ("Can a machine display general intelligence?"), some versions of computationalism make the claim that (as Hobbes wrote):
In other words, our intelligence derives from a form of calculation, similar to arithmetic
. This is the physical symbol system
hypothesis discussed above, and it implies that artificial intelligence is possible. In terms of the philosophical question of AI ("Can a machine have mind, mental states and consciousness?"), most versions of computationalism claim that (as Stevan Harnad
characterizes it):
This is John Searle's "strong AI" discussed above, and it is the real target of the Chinese Room
argument (according to Harnad
).
Turing argues that these objections are often based on naive assumptions about the versatility of machines or are "disguised forms of the argument from consciousness". Writing a program that exhibits one of these behaviors "will not make much of an impression." All of these arguments are tangential to the basic premise of AI, unless it can be shown that one of these traits is essential for general intelligence.
believes that "robots in general will be quite emotional about being nice people" and describes emotions in terms of the behaviors they cause. Fear is a source of urgency. Empathy is a necessary component of good human computer interaction. He says robots "will try to please you in an apparently selfless manner because it will get a thrill out of this positive reinforcement. You can interpret this as a kind of love." Daniel Crevier
writes "Moravec's point is that emotions are just devices for channeling behavior in a direction beneficial to the survival of one's species."
The question of whether the machine actually feels an emotion, or whether it merely acts as if feeling an emotion is the philosophical question, "can a machine be conscious?" in another form.
writers as a name for the essential
human property that makes a character fully human. Turing
strips away all other properties of human beings and reduces the question to "can a machine be the subject of its own thought?" Can it think about itself? Viewed in this way, it is obvious that a program can be written that can report on its own internal states, such as a debugger
.
's Automated Mathematician
, as one example, combined ideas to discover new mathematical truths.)
In 2009, scientists at Aberystwyth University in Wales and the U.K's University of Cambridge designed a robot called Adam that they believe to be the first machine to independently come up with new scientific findings. Also in 2009, researchers at Cornell developed Eureqa, a computer program that extrapolates formulas to fit the data inputted, such as finding the laws of motion from a pendulum's motion.
has suggested that a moment may come when some computers are more intelligent than humans. He calls this "the Singularity
." He suggests that it may be somewhat or possibly very dangerous for humans. This is discussed by a philosophy called Singularitarianism
.
In 2009, academics and technical experts attended a conference to discuss the potential impact of robots and computers and the impact of the hypothetical possibility that they could become self-sufficient and able to make their own decisions. They discussed the possibility and the extent to which computers and robots might be able to acquire any level of autonomy, and to what degree they could use such abilities to possibly pose any threat or hazard. They noted that some machines have acquired various forms of semi-autonomy, including being able to find power sources on their own and being able to independently choose targets to attack with weapons. They also noted that some computer viruses can evade elimination and have achieved "cockroach intelligence." They noted that self-awareness as depicted in science-fiction is probably unlikely, but that there were other potential hazards and pitfalls.
Some experts and academics have questioned the use of robots for military combat, especially when such robots are given some degree of autonomous functions. The US Navy has funded a report which indicates that as military robots become more complex, there should be greater attention to implications of their ability to make autonomous decisions.
The President of the Association for the Advancement of Artificial Intelligence
has commissioned a study to look at this issue. They point to programs like the Language Acquisition Device
which can emulate human interaction.
Some have suggested a need to build "Friendly AI", meaning that the advances which are already occurring with AI should also include an effort to make AI intrinsically friendly and humane.
Alan Turing called this “the theological objection” and writes
Artificial intelligence
Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...
attempts to answer such questions as:
- Can a machine act intelligently? Can it solve any problem that a person would solve by thinking?
- Can a machine have a mindPhilosophy of mindPhilosophy of mind is a branch of philosophy that studies the nature of the mind, mental events, mental functions, mental properties, consciousness and their relationship to the physical body, particularly the brain. The mind-body problem, i.e...
, mental states and consciousnessConsciousnessConsciousness is a term that refers to the relationship between the mind and the world with which it interacts. It has been defined as: subjectivity, awareness, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind...
in the same sense humans do? Can it feel? - Are human intelligence and machine intelligence the same? Is the human brainHuman brainThe human brain has the same general structure as the brains of other mammals, but is over three times larger than the brain of a typical mammal with an equivalent body size. Estimates for the number of neurons in the human brain range from 80 to 120 billion...
essentially a computer?
These three questions reflect the divergent interests of AI researchers
Artificial intelligence
Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...
, philosopher
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
s and cognitive scientists
Cognitive science
Cognitive science is the interdisciplinary scientific study of mind and its processes. It examines what cognition is, what it does and how it works. It includes research on how information is processed , represented, and transformed in behaviour, nervous system or machine...
respectively. The answers to these questions depend on how one defines "intelligence" or "consciousness" and exactly which "machines" are under discussion.
Important proposition
Proposition
In logic and philosophy, the term proposition refers to either the "content" or "meaning" of a meaningful declarative sentence or the pattern of symbols, marks, or sounds that make up a meaningful declarative sentence...
s in the philosophy of AI include:
- Turing's "polite convention"Turing testThe Turing test is a test of a machine's ability to exhibit intelligent behaviour. In Turing's original illustrative example, a human judge engages in a natural language conversation with a human and a machine designed to generate performance indistinguishable from that of a human being. All...
: If a machine acts as intelligently as a human being, then it is as intelligent as a human being. - The Dartmouth proposal: "Every aspect of learning or any other feature of intelligence can be so precisely described that a machine can be made to simulate it."
- NewellAllen NewellAllen Newell was a researcher in computer science and cognitive psychology at the RAND corporation and at Carnegie Mellon University’s School of Computer Science, Tepper School of Business, and Department of Psychology...
and SimonHerbert SimonHerbert Alexander Simon was an American political scientist, economist, sociologist, and psychologist, and professor—most notably at Carnegie Mellon University—whose research ranged across the fields of cognitive psychology, cognitive science, computer science, public administration, economics,...
's physical symbol systemPhysical symbol systemA physical symbol system takes physical patterns , combining them into structures and manipulating them to produce new expressions....
hypothesis: "A physical symbol system has the necessary and sufficient means of general intelligent action." - SearleJohn SearleJohn Rogers Searle is an American philosopher and currently the Slusser Professor of Philosophy at the University of California, Berkeley.-Biography:...
's strong AI hypothesis: "The appropriately programmed computer with the right inputs and outputs would thereby have a mind in exactly the same sense human beings have minds." - HobbesThomas HobbesThomas Hobbes of Malmesbury , in some older texts Thomas Hobbs of Malmsbury, was an English philosopher, best known today for his work on political philosophy...
' mechanism: "Reason is nothing but reckoning."
Can a machine display general intelligence?
Is it possible to create a machine that can solve all the problems humans solve using their intelligence? This is the question that AI researchers are most interested in answering. It defines the scope of what machines will be able to do in the future and guides the direction of AI research. It only concerns the behavior of machines and ignores the issues of interest to psychologistsPsychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...
, cognitive scientists and philosophers
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
; to answer this question, it does not matter whether a machine is really thinking (as a person thinks) or is just acting like it is thinking.
The basic position of most AI researchers is summed up in this statement, which appeared in the proposal for the Dartmouth Conferences of 1956:
- Every aspect of learning or any other feature of intelligence can be so precisely described that a machine can be made to simulate it.
Arguments against the basic premise must show that building a working AI system is impossible, because there is some practical limit to the abilities of computers or that there is some special quality of the human mind that is necessary for thinking and yet cannot be duplicated by a machine (or by the methods of current AI research). Arguments in favor of the basic premise must show that such a system is possible.
The first step to answering the question is to clearly define "intelligence."
Turing test
Alan TuringAlan Turing
Alan Mathison Turing, OBE, FRS , was an English mathematician, logician, cryptanalyst, and computer scientist. He was highly influential in the development of computer science, providing a formalisation of the concepts of "algorithm" and "computation" with the Turing machine, which played a...
, in a famous and seminal 1950 paper, reduced the problem of defining intelligence to a simple question about conversation. He suggests that: if a machine can answer any question put to it, using the same words that an ordinary person would, then we may call that machine intelligent. A modern version of his experimental design would use an online chat room
Chat room
The term chat room, or chatroom, is primarily used by mass media to describe any form of synchronous conferencing, occasionally even asynchronous conferencing...
, where one of the participants is a real person and one of the participants is a computer program. The program passes the test if no one can tell which of the two participants is human. Turing notes that no one (except philosophers) ever asks the question "can people think?" He writes "instead of arguing continually over this point, it is usual to have a polite convention that everyone thinks." Turing's test extends this polite convention to machines:
- If a machine acts as intelligently as human being, then it is as intelligent as a human being.
Human intelligence vs. intelligence in general
One criticism of the Turing testTuring test
The Turing test is a test of a machine's ability to exhibit intelligent behaviour. In Turing's original illustrative example, a human judge engages in a natural language conversation with a human and a machine designed to generate performance indistinguishable from that of a human being. All...
is that it is explicitly anthropomorphic. If our ultimate goal is to create machines that are more intelligent than people, why should we insist that our machines must closely resemble people? Russell
Stuart J. Russell
Stuart Russell is a computer scientist known for his contributions to artificial intelligence.Stuart Russell was born in Portsmouth, England. He received his Bachelor of Arts degree with first-class honours in Physics from Wadham College, Oxford in 1982, and his Ph.D. in Computer Science from...
and Norvig
Peter Norvig
Peter Norvig is an American computer scientist. He is currently the Director of Research at Google Inc.-Educational Background:...
write that "aeronautical engineering texts do not define the goal of their field as 'making machines that fly so exactly like pigeons that they can fool other pigeons.'" Recent AI research defines intelligence in terms of intelligent agent
Intelligent agent
In artificial intelligence, an intelligent agent is an autonomous entity which observes through sensors and acts upon an environment using actuators and directs its activity towards achieving goals . Intelligent agents may also learn or use knowledge to achieve their goals...
s. An "agent" is something which perceives and acts in an environment. A "performance measure" defines what counts as success for the agent.
- If an agent acts so as maximize the expected value of a performance measure based on past experience and knowledge then it is intelligent.
Definitions like this one try to capture the essence of intelligence. They have the advantage that, unlike the Turing test, they do not also test for human traits that we may not want to consider intelligent, like the ability to be insulted or the temptation to lie. They have the disadvantage that they fail to make the commonsense differentiation between "things that think" and "things that do not". By this definition, even a thermostat has a rudimentary intelligence and consciousness.
The brain can be simulated
Marvin MinskyMarvin Minsky
Marvin Lee Minsky is an American cognitive scientist in the field of artificial intelligence , co-founder of Massachusetts Institute of Technology's AI laboratory, and author of several texts on AI and philosophy.-Biography:...
writes that "if the nervous system obeys the laws of physics and chemistry, which we have every reason to suppose it does, then .... we ... ought to be able to reproduce the behavior of the nervous system with some physical device." This argument, first introduced as early as 1943 and vividly described by Hans Moravec
Hans Moravec
Hans Moravec is an adjunct faculty member at the Robotics Institute of Carnegie Mellon University. He is known for his work on robotics, artificial intelligence, and writings on the impact of technology. Moravec also is a futurist with many of his publications and predictions focusing on...
in 1988, is now associated with futurist Ray Kurzweil, who estimates that computer power will be sufficient for a complete brain simulation by the year 2029. A non-real-time simulation of a thalamocortical model that has the size of the human brain (1011 neurons) was performed in 2005 and it took 50 days to simulate 1 second of brain dynamics on a cluster of 27 processors (see also ).
Few disagree that a brain simulation is possible in theory, even critics of AI such as Hubert Dreyfus
Hubert Dreyfus
Hubert Lederer Dreyfus is an American philosopher. He is a professor of philosophy at the University of California, Berkeley....
and John Searle.
However, Searle points out that, in principle, anything can be simulated by a computer, and so any process at all can be considered "computation", if you're willing to stretch the definition to the breaking point. "What we wanted to know is what distinguishes the mind from thermostats and livers," he writes. Any argument that involves simply copying a brain is an argument that admits that we know nothing about how intelligence works. "If we had to know how the brain worked to do AI, we wouldn't bother with AI," writes Searle.
Human thinking is symbol processing
In 1963, Allen NewellAllen Newell
Allen Newell was a researcher in computer science and cognitive psychology at the RAND corporation and at Carnegie Mellon University’s School of Computer Science, Tepper School of Business, and Department of Psychology...
and Herbert Simon
Herbert Simon
Herbert Alexander Simon was an American political scientist, economist, sociologist, and psychologist, and professor—most notably at Carnegie Mellon University—whose research ranged across the fields of cognitive psychology, cognitive science, computer science, public administration, economics,...
proposed that "symbol manipulation" was the essence of both human and machine intelligence. They wrote:
- A physical symbol system has the necessary and sufficient means of general intelligent action.
This claim is very strong: it implies both that human thinking is a kind of symbol manipulation (because a symbol system is necessary for intelligence) and that machines can be intelligent (because a symbol system is sufficient for intelligence). Another version of this position was described by philosopher Hubert Dreyfus, who called it "the psychological assumption":
- The mind can be viewed as a device operating on bits of information according to formal rules.
A distinction is usually made between the kind of high level symbols that directly correspond with objects in the world, such as
Neural network
The term neural network was traditionally used to refer to a network or circuit of biological neurons. The modern usage of the term often refers to artificial neural networks, which are composed of artificial neurons or nodes...
. Early research into AI, called "good old fashioned artificial intelligence" (GOFAI
GOFAI
In artificial intelligence research, GOFAI describes the oldest original approach to achieving artificial intelligence, based on logic and problem solving...
) by John Haugeland
John Haugeland
John Haugeland was a professor of philosophy at the University of Chicago from 1999 until his death. He was chair of the philosophy department from 2004-2007. He spent at most of his career teaching at the University of Pittsburgh...
, focused on these kind of high level symbols.
Arguments against symbol processing
These arguments show that human thinking does not consist (solely) of high level symbol manipulation. They do not show that artificial intelligence is impossible, only that more than symbol processing is required.Lucas, Penrose and Gödel
In 1931, Kurt Gödel
Kurt Gödel
Kurt Friedrich Gödel was an Austrian logician, mathematician and philosopher. Later in his life he emigrated to the United States to escape the effects of World War II. One of the most significant logicians of all time, Gödel made an immense impact upon scientific and philosophical thinking in the...
proved that it is always possible to create statement
Statement (logic)
In logic a statement is either a meaningful declarative sentence that is either true or false, or what is asserted or made by the use of a declarative sentence...
s that a formal system
Formal system
In formal logic, a formal system consists of a formal language and a set of inference rules, used to derive an expression from one or more other premises that are antecedently supposed or derived . The axioms and rules may be called a deductive apparatus...
(such as a high-level symbol manipulation program) could not prove. A human being, however, can (with some thought) see the truth of these "Gödel statements". This proved to philosopher John Lucas
John Lucas (philosopher)
- Overview :John Lucas was educated at Winchester College and Balliol College, Oxford, where he studied first mathematics, then Greats , obtaining first class honors, and proceeding to an MA in Philosophy in 1954. He spent the 1957-58 academic year at Princeton University, deepening his...
that human reason would always be superior to machines. He wrote "Gödel's theorem seems to me to prove that mechanism is false, that is, that minds cannot be explained as machines."
Roger Penrose
Roger Penrose
Sir Roger Penrose OM FRS is an English mathematical physicist and Emeritus Rouse Ball Professor of Mathematics at the Mathematical Institute, University of Oxford and Emeritus Fellow of Wadham College...
expanded on this argument in his 1989 book The Emperor's New Mind
The Emperor's New Mind
The Emperor's New Mind: Concerning Computers, Minds and The Laws of Physics is a 1989 book by mathematical physicist Sir Roger Penrose.Penrose presents the argument that human consciousness is non-algorithmic, and thus is not capable of being modeled by a conventional Turing machine-type of digital...
, where he speculated that quantum mechanical processes inside individual neurons gave humans this special advantage over machines.
Douglas Hofstadter
Douglas Hofstadter
Douglas Richard Hofstadter is an American academic whose research focuses on consciousness, analogy-making, artistic creation, literary translation, and discovery in mathematics and physics...
, in his Pulitzer prize
Pulitzer Prize
The Pulitzer Prize is a U.S. award for achievements in newspaper and online journalism, literature and musical composition. It was established by American publisher Joseph Pulitzer and is administered by Columbia University in New York City...
winning book Gödel, Escher, Bach: An Eternal Golden Braid, explains that these "Gödel-statements" always refer to the system itself, similar to the way the Epimenides paradox
Epimenides paradox
The Epimenides paradox is a problem in logic. It is named after the Cretan philosopher Epimenides of Knossos , There is no single statement of the problem; a typical variation is given in the book Gödel, Escher, Bach, by Douglas Hofstadter:...
uses statements that refer to themselves, such as "this statement is false" or "I am lying". But, of course, the Epimenides paradox
Epimenides paradox
The Epimenides paradox is a problem in logic. It is named after the Cretan philosopher Epimenides of Knossos , There is no single statement of the problem; a typical variation is given in the book Gödel, Escher, Bach, by Douglas Hofstadter:...
applies to anything that makes statements, whether they are machines or humans, even Lucas himself. Consider:
- Lucas can't assert the truth of this statement.
This statement is true but cannot be asserted by Lucas. This shows that Lucas himself is subject to the same limits that he describes for machines, as are all people, and so Lucas
John Lucas (philosopher)
- Overview :John Lucas was educated at Winchester College and Balliol College, Oxford, where he studied first mathematics, then Greats , obtaining first class honors, and proceeding to an MA in Philosophy in 1954. He spent the 1957-58 academic year at Princeton University, deepening his...
's argument is pointless.
Further, Russell and Norvig note that Gödel's argument only applies to what can theoretically be proved, given an infinite amount of memory and time. In practice, real machines (including humans) have finite resources and will have difficulty proving many theorems. It is not necessary to prove everything in order to be intelligent.
Dreyfus: the primacy of unconscious skills
Hubert Dreyfus argued that human intelligence and expertise depended primarily on unconscious instincts rather than conscious symbolic manipulation, and argued that these unconscious skills would never be captured in formal rules.
Dreyfus
Hubert Dreyfus
Hubert Lederer Dreyfus is an American philosopher. He is a professor of philosophy at the University of California, Berkeley....
's argument had been anticipated by Turing in his 1950 paper Computing machinery and intelligence
Computing machinery and intelligence
Computing Machinery and Intelligence, written by Alan Turing and published in 1950 in Mind, is a seminal paper on the topic of artificial intelligence in which the concept of what is now known as the Turing test was introduced to a wide audience....
, where he had classified this as the "argument from the informality of behavior." Turing argued in response that, just because we do not know the rules that govern a complex behavior, this does not mean that no such rules exist. He wrote: "we cannot so easily convince ourselves of the absence of complete laws of behaviour ... The only way we know of for finding such laws is scientific observation, and we certainly know of no circumstances under which we could say, 'We have searched enough. There are no such laws.'"
Russell and Norvig
Peter Norvig
Peter Norvig is an American computer scientist. He is currently the Director of Research at Google Inc.-Educational Background:...
point out that, in the years since Dreyfus published his critique, progress has been made towards discovering the "rules" that govern unconscious reasoning. The situated
Situated
In artificial intelligence and cognitive science, the term situated refers to an agent which is embedded in an environment. The term situated is commonly used to refer to robots, but some researchers argue that software agents can also be situated if:...
movement in robotics
Robotics
Robotics is the branch of technology that deals with the design, construction, operation, structural disposition, manufacture and application of robots...
research attempts to capture our unconscious skills at perception and attention. Computational intelligence
Computational intelligence
Computational intelligence is a set of Nature-inspired computational methodologies and approaches to address complex problems of the real world applications to which traditional methodologies and approaches are ineffective or infeasible. It primarily includes Fuzzy logic systems, Neural Networks...
paradigms, such as neural nets, evolutionary algorithm
Evolutionary algorithm
In artificial intelligence, an evolutionary algorithm is a subset of evolutionary computation, a generic population-based metaheuristic optimization algorithm. An EA uses some mechanisms inspired by biological evolution: reproduction, mutation, recombination, and selection...
s and so on are mostly directed at simulated unconscious reasoning and learning. Research into commonsense knowledge has focused on reproducing the "background" or context of knowledge. In fact, AI research in general has moved away from high level symbol manipulation or "GOFAI
GOFAI
In artificial intelligence research, GOFAI describes the oldest original approach to achieving artificial intelligence, based on logic and problem solving...
", towards new models that are intended to capture more of our unconscious reasoning. Historian and AI researcher Daniel Crevier
Daniel Crevier
Daniel Crevier is a Canadian entrepreneur and artificial intelligence and image processing researcher. He is also the author of AI: the Tumultuous History of the Search for Artificial Intelligence. In 1974 Crevier received a Ph.D. degree from Massachusetts Institute of Technology...
wrote that "time has proven the accuracy and perceptiveness of some of Dreyfus's comments. Had he formulated them less aggressively, constructive actions they suggested might have been taken much earlier."
Can a machine have a mind, consciousness and mental states?
This is a philosophical question, related to the problem of other mindsProblem of other minds
The problem of other minds has traditionally been regarded as an epistemological challenge raised by the skeptic. The challenge may be expressed as follows: given that I can only observe the behavior of others, how can I know that others have minds? The thought behind the question is that no matter...
and the hard problem of consciousness
Hard problem of consciousness
The hard problem of consciousness is the problem of explaining how and why we have qualitative phenomenal experiences. David Chalmers contrasts this with the "easy problems" of explaining the ability to discriminate, integrate information, report mental states, focus attention, etc...
. The question revolves around a position defined by John Searle as "strong AI":
- A physical symbol system can have a mind and mental states.
Searle distinguished this position from what he called "weak AI":
- A physical symbol system can act intelligently.
Searle introduced the terms to isolate strong AI from weak AI so he could focus on what he thought was the more interesting and debatable issue. He argued that even if we assume that we had a computer program that acted exactly like a human mind, there would still be a difficult philosophical question that needed to be answered.
Neither of Searle's two positions are of great concern to AI research, since they do not directly answer the question "can a machine display general intelligence?" (unless it can also be shown that consciousness is necessary for intelligence). There are a few researchers who believe that consciousness is an essential element in intelligence, such as Igor Aleksander
Igor Aleksander
Igor Aleksander FREng is an emeritus professor of Neural Systems Engineering in the Department of Electrical and Electronic Engineering at Imperial College London...
, Stan Franklin
Stan Franklin
Stan Franklin is an American scientist and W. Harry Feinstone Interdisciplinary Research Professor at the and co-director of the Institute of Intelligent Systems. He is the author of Artificial Minds and mental father of IDA and its successor LIDA, both computational implementations of...
, Ron Sun
Ron Sun
Ron Sun is a cognitive scientist and currently Professor of Cognitive Science at Rensselaer Polytechnic Institute, and formerly the James C. Dowell Professor of Engineering and Professor of Computer Science at University of Missouri...
, and Pentti Haikonen, although their definition of "consciousness" strays very close to "intelligence." See artificial consciousness
Artificial consciousness
Artificial consciousness , also known as machine consciousness or synthetic consciousness, is a field related to artificial intelligence and cognitive robotics whose aim is to define that which would have to be synthesized were consciousness to be found in an engineered artifact .Neuroscience...
. Turing wrote "I do not wish to give the impression that I think there is no mystery about consciousness ... [b]ut I do not think these mysteries necessarily need to be solved before we can answer the question [of whether machines can think]." Russell
Stuart J. Russell
Stuart Russell is a computer scientist known for his contributions to artificial intelligence.Stuart Russell was born in Portsmouth, England. He received his Bachelor of Arts degree with first-class honours in Physics from Wadham College, Oxford in 1982, and his Ph.D. in Computer Science from...
and Norvig agree: "Most AI researchers take the weak AI hypothesis for granted, and don't care about the strong AI hypothesis."
Before we can answer this question, we must be clear what we mean by "minds", "mental states" and "consciousness".
Consciousness, minds, mental states, meaning
The words "mindMind
The concept of mind is understood in many different ways by many different traditions, ranging from panpsychism and animism to traditional and organized religious views, as well as secular and materialist philosophies. Most agree that minds are constituted by conscious experience and intelligent...
" and "consciousness
Consciousness
Consciousness is a term that refers to the relationship between the mind and the world with which it interacts. It has been defined as: subjectivity, awareness, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind...
" are used by different communities in different ways. Some new age
New Age
The New Age movement is a Western spiritual movement that developed in the second half of the 20th century. Its central precepts have been described as "drawing on both Eastern and Western spiritual and metaphysical traditions and then infusing them with influences from self-help and motivational...
thinkers, for example, use the word "consciousness" to describe something similar to Bergson's "élan vital
Élan vital
Élan vital was coined by French philosopher Henri Bergson in his 1907 book Creative Evolution, in which he addresses the question of self-organisation and spontaneous morphogenesis of things in an increasingly complex manner. Elan vital was translated in the English edition as "vital impetus", but...
": an invisible, energetic fluid that permeates life and especially the mind. Science fiction
Science fiction
Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
writers use the word to describe some essential
Essentialism
In philosophy, essentialism is the view that, for any specific kind of entity, there is a set of characteristics or properties all of which any entity of that kind must possess. Therefore all things can be precisely defined or described...
property that makes us human: a machine or alien that is "conscious" will be presented as a fully human character, with intelligence, desires, will, insight, pride and so on. (Science fiction writers also use the words "sentience", "sapience," "self-awareness" or "ghost" (as in the Ghost in the Shell
Ghost in the Shell
is a Japanese multimedia franchise composed of manga, animated films, anime series, video games and novels. It focuses on the activities of the counter-terrorist organization Public Security Section 9 in a futuristic, cyberpunk Japan ....
manga and anime series) to describe this essential human property.) For others, the words "mind" or "consciousness" are used as a kind of secular synonym for the soul
Soul
A soul in certain spiritual, philosophical, and psychological traditions is the incorporeal essence of a person or living thing or object. Many philosophical and spiritual systems teach that humans have souls, and others teach that all living things and even inanimate objects have souls. The...
.
For philosophers
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
, neuroscientists
Neuroscience
Neuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...
and cognitive scientists, the words are used in a way that is both more precise and more mundane: they refer to the familiar, everyday experience of having a "thought in your head", like a perception, a dream, an intention or a plan, and to the way we know something, or mean something or understand something. "It's not hard to give a commonsense definition of consciousness" observes philosopher John Searle. What is mysterious and fascinating is not so much what it is but how it is: how does a lump of fatty tissue and electricity give rise to this (familiar) experience of perceiving, meaning or thinking?
Philosophers call this the hard problem of consciousness
Hard problem of consciousness
The hard problem of consciousness is the problem of explaining how and why we have qualitative phenomenal experiences. David Chalmers contrasts this with the "easy problems" of explaining the ability to discriminate, integrate information, report mental states, focus attention, etc...
. It is the latest version of a classic problem in the philosophy of mind
Philosophy of mind
Philosophy of mind is a branch of philosophy that studies the nature of the mind, mental events, mental functions, mental properties, consciousness and their relationship to the physical body, particularly the brain. The mind-body problem, i.e...
called the "mind-body problem." A related problem is the problem of meaning or understanding (which philosophers call "intentionality
Intentionality
The term intentionality was introduced by Jeremy Bentham as a principle of utility in his doctrine of consciousness for the purpose of distinguishing acts that are intentional and acts that are not...
"): what is the connection between our thoughts and what we are thinking about (i.e. objects and situations out in the world)? A third issue is the problem of experience (or "phenomenology"): If two people see the same thing, do they have the same experience? Or are there things "inside their head" (called "qualia
Qualia
Qualia , singular "quale" , from a Latin word meaning for "what sort" or "what kind," is a term used in philosophy to refer to subjective conscious experiences as 'raw feels'. Examples of qualia are the pain of a headache, the taste of wine, the experience of taking a recreational drug, or the...
") that can be different from person to person?
Neurobiologists believe all these problems will be solved as we begin to identify the neural correlates of consciousness
Neural correlates of consciousness
The neural correlates of consciousness constitute the minimal set of neuronal events and mechanisms sufficient for a specific conscious percept. Neuroscientists use empirical approaches to discover neural correlates of subjective phenomena...
: the actual relationship between the machinery in our heads and its collective properties; such as the mind, experience and understanding. Some of the harshest critics of artificial intelligence
Artificial intelligence
Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...
agree that the brain is just a machine, and that consciousness and intelligence are the result of physical processes in the brain. The difficult philosophical question is this: can a computer program, running on a digital machine that shuffles the binary digits of zero and one, duplicate the ability of the neurons
Neural correlates of consciousness
The neural correlates of consciousness constitute the minimal set of neuronal events and mechanisms sufficient for a specific conscious percept. Neuroscientists use empirical approaches to discover neural correlates of subjective phenomena...
to create minds, with mental state
Mental state
* In psychology, mental state is an indication of a person's mental health**Mental status examination, a structured way of observing and describing a patient's current state of mind...
s (like understanding or perceiving), and ultimately, the experience of consciousness
Consciousness
Consciousness is a term that refers to the relationship between the mind and the world with which it interacts. It has been defined as: subjectivity, awareness, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind...
?
Searle's Chinese room
John Searle asks us to consider a thought experimentThought experiment
A thought experiment or Gedankenexperiment considers some hypothesis, theory, or principle for the purpose of thinking through its consequences...
: suppose we have written a computer program that passes the Turing Test and demonstrates "general intelligent action." Suppose, specifically that the program can converse in fluent Chinese. Write the program on 3x5 cards and give them to an ordinary person who does not speak Chinese. Lock the person into a room and have him follow the instructions on the cards. He will copy out Chinese characters and pass them in and out of the room through a slot. From the outside, it will appear that the Chinese room contains a fully intelligent person who speaks Chinese. The question is this: is there anyone (or anything) in the room that understands Chinese? That is, is there anything that has the mental state
Mental state
* In psychology, mental state is an indication of a person's mental health**Mental status examination, a structured way of observing and describing a patient's current state of mind...
of understanding
Understanding
Understanding is a psychological process related to an abstract or physical object, such as a person, situation, or message whereby one is able to think about it and use concepts to deal adequately with that object....
, or which has conscious
Consciousness
Consciousness is a term that refers to the relationship between the mind and the world with which it interacts. It has been defined as: subjectivity, awareness, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind...
awareness
Awareness
Awareness is the state or ability to perceive, to feel, or to be conscious of events, objects or sensory patterns. In this level of consciousness, sense data can be confirmed by an observer without necessarily implying understanding. More broadly, it is the state or quality of being aware of...
of what is being discussed in Chinese? The man is clearly not aware. The room cannot be aware. The cards certainly aren't aware. Searle concludes that the Chinese room
Chinese room
The Chinese room is a thought experiment by John Searle, which first appeared in his paper "Minds, Brains, and Programs", published in Behavioral and Brain Sciences in 1980...
, or any other physical symbol system, cannot have a mind.
Searle goes on to argue that actual mental state
Mental state
* In psychology, mental state is an indication of a person's mental health**Mental status examination, a structured way of observing and describing a patient's current state of mind...
s and consciousness
Consciousness
Consciousness is a term that refers to the relationship between the mind and the world with which it interacts. It has been defined as: subjectivity, awareness, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind...
require (yet to be described) "actual physical-chemical properties of actual human brains." He argues there are special "causal properties" of brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
s and neuron
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...
s that gives rise to mind
Mind
The concept of mind is understood in many different ways by many different traditions, ranging from panpsychism and animism to traditional and organized religious views, as well as secular and materialist philosophies. Most agree that minds are constituted by conscious experience and intelligent...
s: in his words "brains cause minds."
Related arguments: Leibniz' mill, Block's telephone exchange and blockhead
Gottfried LeibnizGottfried Leibniz
Gottfried Wilhelm Leibniz was a German philosopher and mathematician. He wrote in different languages, primarily in Latin , French and German ....
made essentially the same argument as Searle in 1714, using the thought experiment of expanding the brain until it was the size of a mill. In 1974, Lawrence Davis imagined duplicating the brain using telephone lines and offices staffed by people, and in 1978 Ned Block envisioned the entire population of China involved in such a brain simulation. This thought experiment is called "the Chinese Nation" or "the Chinese Gym". Ned Block also proposed his "blockhead" argument, which is a version of the Chinese room
Chinese room
The Chinese room is a thought experiment by John Searle, which first appeared in his paper "Minds, Brains, and Programs", published in Behavioral and Brain Sciences in 1980...
in which the program has been re-factored into a simple set of rules of the form "see this, do that", removing all mystery from the program.
Responses to the Chinese Room
Responses to the Chinese room emphasize several different points.- The systems reply and the virtual mind reply: This reply argues that the system, including the man, the program, the room, and the cards, is what understands Chinese. Searle claims that the man in the room is the only thing which could possibly "have a mind" or "understand", but others disagree, arguing that it is possible for there to be two minds in the same physical place, similar to the way a computer can simultaneously "be" two machines at once: one physical (like a MacintoshMacintoshThe Macintosh , or Mac, is a series of several lines of personal computers designed, developed, and marketed by Apple Inc. The first Macintosh was introduced by Apple's then-chairman Steve Jobs on January 24, 1984; it was the first commercially successful personal computer to feature a mouse and a...
) and one "virtualVirtual machineA virtual machine is a "completely isolated guest operating system installation within a normal host operating system". Modern virtual machines are implemented with either software emulation or hardware virtualization or both together.-VM Definitions:A virtual machine is a software...
" (like a word processorWord processorA word processor is a computer application used for the production of any sort of printable material....
). - Speed, power and complexity replies: Several critics point out that the man in the room would probably take millions of years to respond to a simple question, and would require "filing cabinets" of astronomical proportions. This brings the clarity of Searle's intuition into doubt.
- Robot reply: To truly understand, some believe the Chinese Room needs eyes and hands. Hans Moravec writes: 'If we could graft a robot to a reasoning program, we wouldn't need a person to provide the meaning anymore: it would come from the physical world."
- Brain simulator reply: What if the program simulates the sequence of nerve firings at the synapses of an actual brain of an actual Chinese speaker? The man in the room would be simulating an actual brain. This is a variation on the "systems reply" that appears more plausible because "the system" now clearly operates like a human brain, which strengthens the intuition that there is something besides the man in the room that could understand Chinese.
- Other minds reply and the epiphenomena reply: Several people have noted that Searle's argument is just a version of the problem of other mindsProblem of other mindsThe problem of other minds has traditionally been regarded as an epistemological challenge raised by the skeptic. The challenge may be expressed as follows: given that I can only observe the behavior of others, how can I know that others have minds? The thought behind the question is that no matter...
, applied to machines. Since it is difficult to decide if people are "actually" thinking, we should not be surprised that it is difficult to answer the same question about machines. A related idea is that Searle's "causal properties" of neurons are epiphenomenal: they have no effect on the real world. Why would natural selection create them in the first place, if they make no difference to behavior?
Is thinking a kind of computation?
This issue is of primary importance to cognitive scientistsCognitive science
Cognitive science is the interdisciplinary scientific study of mind and its processes. It examines what cognition is, what it does and how it works. It includes research on how information is processed , represented, and transformed in behaviour, nervous system or machine...
, who study the nature of human thinking and problem solving.
The computational theory of mind
Computational theory of mind
In philosophy, the computational theory of mind is the view that the human mind is an information processing system and that thinking is a form of computing. The theory was proposed in its modern form by Hilary Putnam in 1961 and developed by Jerry Fodor in the 60s and 70s...
or "computationalism" claims that the relationship between mind and brain is similar (if not identical) to the relationship between a running program and a computer. The idea has philosophical roots in Hobbes (who claimed reasoning was "nothing more than reckoning"), Leibniz (who attempted to create a logical calculus of all human ideas), Hume
David Hume
David Hume was a Scottish philosopher, historian, economist, and essayist, known especially for his philosophical empiricism and skepticism. He was one of the most important figures in the history of Western philosophy and the Scottish Enlightenment...
(who thought perception could be reduced to "atomic impressions") and even Kant
KANT
KANT is a computer algebra system for mathematicians interested in algebraic number theory, performing sophisticated computations in algebraic number fields, in global function fields, and in local fields. KASH is the associated command line interface...
(who analyzed all experience as controlled by formal rules). The latest version is associated with philosophers Hilary Putnam
Hilary Putnam
Hilary Whitehall Putnam is an American philosopher, mathematician and computer scientist, who has been a central figure in analytic philosophy since the 1960s, especially in philosophy of mind, philosophy of language, philosophy of mathematics, and philosophy of science...
and Jerry Fodor
Jerry Fodor
Jerry Alan Fodor is an American philosopher and cognitive scientist. He holds the position of State of New Jersey Professor of Philosophy at Rutgers University and is the author of many works in the fields of philosophy of mind and cognitive science, in which he has laid the groundwork for the...
.
This question bears on our earlier questions: if the human brain is a kind of computer then computers can be both intelligent and conscious, answering both the practical and philosophical questions of AI. In terms of the practical question of AI ("Can a machine display general intelligence?"), some versions of computationalism make the claim that (as Hobbes wrote):
- Reasoning is nothing but reckoning
In other words, our intelligence derives from a form of calculation, similar to arithmetic
Arithmetic
Arithmetic or arithmetics is the oldest and most elementary branch of mathematics, used by almost everyone, for tasks ranging from simple day-to-day counting to advanced science and business calculations. It involves the study of quantity, especially as the result of combining numbers...
. This is the physical symbol system
Physical symbol system
A physical symbol system takes physical patterns , combining them into structures and manipulating them to produce new expressions....
hypothesis discussed above, and it implies that artificial intelligence is possible. In terms of the philosophical question of AI ("Can a machine have mind, mental states and consciousness?"), most versions of computationalism claim that (as Stevan Harnad
Stevan Harnad
Stevan Harnad is a cognitive scientist.- Career :Harnad was born in Budapest, Hungary. He did his undergraduate work at McGill University and his graduate work at Princeton University's Department of Psychology...
characterizes it):
- Mental states are just implementations of (the right) computer programs
This is John Searle's "strong AI" discussed above, and it is the real target of the Chinese Room
Chinese room
The Chinese room is a thought experiment by John Searle, which first appeared in his paper "Minds, Brains, and Programs", published in Behavioral and Brain Sciences in 1980...
argument (according to Harnad
Stevan Harnad
Stevan Harnad is a cognitive scientist.- Career :Harnad was born in Budapest, Hungary. He did his undergraduate work at McGill University and his graduate work at Princeton University's Department of Psychology...
).
Other related questions
Alan Turing noted that there are many arguments of the form "a machine will never do X", where X can be many things, such as:Be kind, resourceful, beautiful, friendly, have initiative, have a sense of humor, tell right from wrong, make mistakes, fall in love, enjoy strawberries and cream, make someone 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.
Turing argues that these objections are often based on naive assumptions about the versatility of machines or are "disguised forms of the argument from consciousness". Writing a program that exhibits one of these behaviors "will not make much of an impression." All of these arguments are tangential to the basic premise of AI, unless it can be shown that one of these traits is essential for general intelligence.
Can a machine have emotions?
Hans MoravecHans Moravec
Hans Moravec is an adjunct faculty member at the Robotics Institute of Carnegie Mellon University. He is known for his work on robotics, artificial intelligence, and writings on the impact of technology. Moravec also is a futurist with many of his publications and predictions focusing on...
believes that "robots in general will be quite emotional about being nice people" and describes emotions in terms of the behaviors they cause. Fear is a source of urgency. Empathy is a necessary component of good human computer interaction. He says robots "will try to please you in an apparently selfless manner because it will get a thrill out of this positive reinforcement. You can interpret this as a kind of love." Daniel Crevier
Daniel Crevier
Daniel Crevier is a Canadian entrepreneur and artificial intelligence and image processing researcher. He is also the author of AI: the Tumultuous History of the Search for Artificial Intelligence. In 1974 Crevier received a Ph.D. degree from Massachusetts Institute of Technology...
writes "Moravec's point is that emotions are just devices for channeling behavior in a direction beneficial to the survival of one's species."
The question of whether the machine actually feels an emotion, or whether it merely acts as if feeling an emotion is the philosophical question, "can a machine be conscious?" in another form.
Can a machine be self aware?
"Self awareness", as noted above, is sometimes used by science fictionScience fiction
Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
writers as a name for the essential
Essentialism
In philosophy, essentialism is the view that, for any specific kind of entity, there is a set of characteristics or properties all of which any entity of that kind must possess. Therefore all things can be precisely defined or described...
human property that makes a character fully human. Turing
Alan Turing
Alan Mathison Turing, OBE, FRS , was an English mathematician, logician, cryptanalyst, and computer scientist. He was highly influential in the development of computer science, providing a formalisation of the concepts of "algorithm" and "computation" with the Turing machine, which played a...
strips away all other properties of human beings and reduces the question to "can a machine be the subject of its own thought?" Can it think about itself? Viewed in this way, it is obvious that a program can be written that can report on its own internal states, such as a debugger
Debugger
A debugger or debugging tool is a computer program that is used to test and debug other programs . The code to be examined might alternatively be running on an instruction set simulator , a technique that allows great power in its ability to halt when specific conditions are encountered but which...
.
Can a machine be original or creative?
Turing reduces this to the question of whether a machine can “take us by surprise" and argues that this is obviously true, as any programmer can attest. He notes that, with enough storage capacity, a computer can behave in an astronomical number of different ways. It must be possible, even trivial, for a computer that can represent ideas to combine them in new ways. (Douglas LenatDouglas Lenat
Douglas B. Lenat is the CEO of Cycorp, Inc. of Austin, Texas, and has been a prominent researcher in artificial intelligence, especially machine learning , knowledge representation, blackboard systems, and "ontological engineering"...
's Automated Mathematician
Automated Mathematician
The Automated Mathematician is one of the earliest successful discovery systems. It was created by Doug Lenat in Lisp, and in 1977 led to Lenat being awarded the IJCAI Computers and Thought Award....
, as one example, combined ideas to discover new mathematical truths.)
In 2009, scientists at Aberystwyth University in Wales and the U.K's University of Cambridge designed a robot called Adam that they believe to be the first machine to independently come up with new scientific findings. Also in 2009, researchers at Cornell developed Eureqa, a computer program that extrapolates formulas to fit the data inputted, such as finding the laws of motion from a pendulum's motion.
Can a machine be benevolent or hostile?
Vernor VingeVernor Vinge
Vernor Steffen Vinge is a retired San Diego State University Professor of Mathematics, computer scientist, and science fiction author. He is best known for his Hugo Award-winning novels and novellas A Fire Upon the Deep , A Deepness in the Sky , Rainbows End , Fast Times at Fairmont High ...
has suggested that a moment may come when some computers are more intelligent than humans. He calls this "the Singularity
Technological singularity
Technological singularity refers to the hypothetical future emergence of greater-than-human intelligence through technological means. Since the capabilities of such an intelligence would be difficult for an unaided human mind to comprehend, the occurrence of a technological singularity is seen as...
." He suggests that it may be somewhat or possibly very dangerous for humans. This is discussed by a philosophy called Singularitarianism
Singularitarianism
Singularitarianism is a technocentric ideology and social movement defined by the belief that a technological singularity—the creation of a superintelligence—will likely happen in the medium future, and that deliberate action ought to be taken to ensure that the Singularity benefits...
.
In 2009, academics and technical experts attended a conference to discuss the potential impact of robots and computers and the impact of the hypothetical possibility that they could become self-sufficient and able to make their own decisions. They discussed the possibility and the extent to which computers and robots might be able to acquire any level of autonomy, and to what degree they could use such abilities to possibly pose any threat or hazard. They noted that some machines have acquired various forms of semi-autonomy, including being able to find power sources on their own and being able to independently choose targets to attack with weapons. They also noted that some computer viruses can evade elimination and have achieved "cockroach intelligence." They noted that self-awareness as depicted in science-fiction is probably unlikely, but that there were other potential hazards and pitfalls.
Some experts and academics have questioned the use of robots for military combat, especially when such robots are given some degree of autonomous functions. The US Navy has funded a report which indicates that as military robots become more complex, there should be greater attention to implications of their ability to make autonomous decisions.
The President of the Association for the Advancement of Artificial Intelligence
Association for the Advancement of Artificial Intelligence
The Association for the Advancement of Artificial Intelligence or AAAI is an international, nonprofit, scientific society devoted to advancing the scientific understanding of the mechanisms underlying thought and intelligent behavior and their embodiment in machines...
has commissioned a study to look at this issue. They point to programs like the Language Acquisition Device
Language Acquisition Device (computer)
The Language Acquisition Device is a computer program developed by Lobal Technologies, a computer company in the United Kingdom, and scientists from King's College. It emulates the functions of the brain's frontal lobes where humans process language and emotion....
which can emulate human interaction.
Some have suggested a need to build "Friendly AI", meaning that the advances which are already occurring with AI should also include an effort to make AI intrinsically friendly and humane.
Can a machine have a soul?
Finally, some who believe in the existence of a soul would argue that- Thinking is a function of man’s immortal soul
Alan Turing called this “the theological objection” and writes
In attempting to construct such machines we should not be irreverently usurping His power of creating souls, any more than we are in the procreation of children: rather we are, in either case, instruments of His will providing mansions for the souls that He creates.
See also
- Artificial brainArtificial brainArtificial brain is a term commonly used in the media to describe research that aims to develop software and hardware with cognitive abilities similar to the animal or human brain...
- Artificial intelligenceArtificial intelligenceArtificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...
- ChatterbotChatterbotA chatter robot, chatterbot, chatbot, or chat bot is a computer program designed to simulate an intelligent conversation with one or more human users via auditory or textual methods, primarily for engaging in small talk. The primary aim of such simulation has been to fool the user into thinking...
- Chinese roomChinese roomThe Chinese room is a thought experiment by John Searle, which first appeared in his paper "Minds, Brains, and Programs", published in Behavioral and Brain Sciences in 1980...
- Computational theory of mindComputational theory of mindIn philosophy, the computational theory of mind is the view that the human mind is an information processing system and that thinking is a form of computing. The theory was proposed in its modern form by Hilary Putnam in 1961 and developed by Jerry Fodor in the 60s and 70s...
- Computing Machinery and IntelligenceComputing machinery and intelligenceComputing Machinery and Intelligence, written by Alan Turing and published in 1950 in Mind, is a seminal paper on the topic of artificial intelligence in which the concept of what is now known as the Turing test was introduced to a wide audience....
- Brain (other matters section)
- Dreyfus' critique of artificial intelligence
- FunctionalismFunctionalism (philosophy of mind)Functionalism is a theory of the mind in contemporary philosophy, developed largely as an alternative to both the identity theory of mind and behaviourism. Its core idea is that mental states are constituted solely by their functional role — that is, they are causal relations to other mental...
- Philosophy of computer sciencePhilosophy of computer scienceThe philosophy of computer science is concerned with the philosophical questions that arise with the study of computer science, which is understood to mean not just programming but the whole study of concepts and methodologies that assist in the development and maintenance of computer systems...
- Philosophy of informationPhilosophy of informationThe philosophy of information is the area of research that studies conceptual issues arising at the intersection of computer science, information technology, and philosophy.It includes:...
- Philosophy of mindPhilosophy of mindPhilosophy of mind is a branch of philosophy that studies the nature of the mind, mental events, mental functions, mental properties, consciousness and their relationship to the physical body, particularly the brain. The mind-body problem, i.e...
- Physical symbol systemPhysical symbol systemA physical symbol system takes physical patterns , combining them into structures and manipulating them to produce new expressions....
- Synthetic intelligenceSynthetic intelligenceSynthetic intelligence is an alternative term for artificial intelligence which emphasizes that the intelligence of machines need not be an imitation or any way artificial; it can be a genuine form of intelligence. John Haugeland proposes an analogy with artificial and synthetic diamonds—only the...
- Turing TestTuring testThe Turing test is a test of a machine's ability to exhibit intelligent behaviour. In Turing's original illustrative example, a human judge engages in a natural language conversation with a human and a machine designed to generate performance indistinguishable from that of a human being. All...