HOW EMPIRICISM DISTORTS AI AND ROBOTICS Dr Antoni Diller School of Computer Science University of Birmingham Birmingham, B15 2TT, UK email: [email protected] Abstract rently, Cog has no legs, but it does have robotic arms and a head with video cameras for eyes. It is one of the most im- The main goal of AI and Robotics is that of creating a hu- pressive robots around as it can recognise various physical manoid robot that can interact with human beings. Such an objects, distinguish living from non-living things and im- android would have to have the ability to acquire knowl- itate what it sees people doing. Cynthia Breazeal worked edge about the world it inhabits. Currently, the gaining of with Cog when she was one of Brooks’s graduate students. beliefs through testimony is hardly investigated in AI be- She said that after she became accustomed to Cog’s strange cause researchers have uncritically accepted empiricism. appearance interacting with it felt just like playing with a Great emphasis is placed on perception as a source of baby and it was easy to imagine that Cog was alive. knowledge. It is important to understand perception, but There are several major research projects in Japan. A even more important is an understanding of testimony. A common rationale given by scientists engaged in these is sketch of a theory of testimony is presented and an appeal the need to provide for Japan’s ageing population. They say for more research is made. their robots will eventually act as carers for those unable to look after themselves. The robot carers would look after Keywords the physical needs of those in their care and also, presum- ably, they would be companions to their elderly or disabled Knowledge acquisition, testimony, evaluating information, charges. Having robot carers would free up humans to do world knowledge. more economically profitable work. One of the most advanced Japanese machines is the Introduction Honda P3. This looks like a man wearing a spacesuit, but it is made entirely of electronic and mechanical components. Especially since the creation of the science-fiction genre, It is capable of walking, going up and down stairs and open- the idea of creating artificial beings in human form has ing doors. The team that designed and built the P3 was gripped many people’s imagination. For example, Fritz led by Masato Hirose and the development took place at Lang’s 1927 film Metropolis features a metallic robot that Honda’s Wako Research and Development Laboratory [11, is transformed in a memorable scene into the likeness of pp. 42–45]. Maria. The real Maria is a saint who comforts the op- Unfortunately, despite their technological sophistica- pressed workers whereas the android is an agent provoca- tion none of these projects will succeed in producing an- teur who incites a riot which provides a pretext for John droids that behave like their fictional counterparts. I do Frederson, the ruler of Metropolis, to crush the rebellious not want to belittle the great scientific and technological spirit of the workers. The intricacies of the plot of Metropo- progress that has already been made. Researchers have had lis need not concern us here, but what I would like to single to solve many difficult problems in order to build humanoid out is the fact that the android is able to pass undetected robots that can walk on two legs, climb stairs, grasp objects as Maria. It comes as a real shock to the watching crowd without breaking them, recognise different kinds of phys- when the android changes back into its original metallic ical object, imitate the human behaviour that they see and form. Much more could be said about the exploits of fic- so on. However, because of their shared assumptions about tional robots, including Rachel in Blade Runner, the killing knowledge, none of these high-profile projects will ever re- android in Terminator, Lieutenant Commander Data in Star sult in an android that can interact meaningfully with a hu- Trek: The Next Generation and David in Spielberg’s film man being and engage in intelligent conversation with that AI, but what of the reality? person. The fundamental human ability that virtually all There are a number of important research projects in researchers have overlooked is that of learning from oth- the USA whose goal is the manufacture of a humanoid ers by believing what they say and by accepting what they robot. One of the best-known of these projects is headed have written. These scientists have ignored the role of tes- by Rodney Brooks of the Massachusetts Institute of Tech- timony in human belief-acquisition. There are still many nology [11, pp. 58–65]. His robot is called ‘Cog’. Cur- outstanding problems to be solved before artificial natural- language processing is as good as the human ability to un- people may deny the fact it is nonetheless true that sci- derstand language, but I am not concerned with seman- ence and philosophy are inextricable linked. This is es- tic issues in this paper. My interests are epistemological. pecially true of that branch of philosophy, known as episte- I am concerned with how humans and machines acquire mology, which deals with how people acquire knowledge. knowledge about the world in which they live. One of my Einstein, for one, was aware of this connection. He wrote main points is that researchers in AI and Robotics have fo- [9, pp. 683–684], ‘Epistemology without contact with sci- cused almost exclusively on perception as our main source ence becomes an empty scheme. Science without episte- of information about the world and, consequently, have ne- mology is—insofar as it is thinkable at all—primitive and glected the importance of testimony as a source of knowl- muddled.’ It is also true that an incorrect epistemology is edge, although most of the knowledge a person has about just as bad as none at all. The tradition in which scientists the world has been acquired through testimony, that is to building androids work has been profoundly influenced by say, by accepting what other people say and by believing that epistemology known as empiricism and two principles what they have written. The reason for this neglect is that in particular have prevented those scientists from appreciat- they uncritically use an empiricist theory of knowledge, but ing the importance of learning from testimony. The first of before explaining this the importance of testimony needs to these is the principle that statements should not be accepted be demonstrated. unless evidence is provided to support them and the second states that this evidence should be ultimately grounded in sense experience or perception. The Importance of Testimony The main problem with the idea that we should not ac- cept assertions without checking their credentials is that we In order to live in any human society, especially a complex, simply do not have the time to do this. To rationally evalu- technological one, a person needs a great deal of informa- ate any statement we read or hear is a very time-consuming tion and an android would need a similar amount of knowl- process. Thus, the number of statements that we can check edge. Some of this information could be programmed into in this way is very small. For example, a physicist wanting the robot before it entered society, but not all of it. One to make use of Planck’s constant or the value of the speed of of the reasons for this is that the android would need to light in a vacuum would look up their values in a standard have knowledge about things that change over time. This reference book trusting that they had been correctly worked is especially true of those things that people talk about with out. Their values are taken on trust and this saves the physi- each other on a daily basis and an android employed as a cist wanting to use those values a great deal of time. On a carer for an elderly person, say, would have to be able to en- small number of occasions a few people recalculate the val- gage in such conversation. For example, people talk about ues of these constants, but this does not happen very often. the weather, what their neighbours and friends are getting I am not suggesting that we should never check any of our up to, the current political situation, how their football team beliefs. Just because we cannot rationally evaluate all our is doing, recent advances in science and so on. Information beliefs it does not follow that we should not check any of about these topics is obtained from various sources includ- them. In fact, there are occasions when it is important for ing the radio, television, newspapers and other people. us to critically examine some of our views in order to weed The android would also have to know about those ac- out error and falsehood. However, the principle that a state- tivities which most people engage in at some time or other, ment should not be accepted unless evidence is provided in namely such things as looking after a home, travelling, its support is not one that anybody could live by. shopping, going on holiday, looking after money, eating The second empiricist principle states that we should in a restaurant and so on. In order to do any of these you only accept a statement if there is perceptual or observa- need to have a considerable amount of information. For tional evidence in its favour.