| • Science | • People | • Locations | • Timeline |
Professor Hubert Dreyfus is an American philosopher and the author of the 1972 book What Computers Can't Do and in 1979 its revision What Computers Still Can't Do. Professor Dreyfus taught at the Massachusetts Institute of Technology between the years of 1960 and 1968. He also taught Frankfurt University and Hamilton College.
In 1964 Dreyfus published Alchemy and Artificial Intelligence, an attack on the work of Allen Newell and Herbert Simon, two of the leading researchers in the field of Artificial Intelligence. Dreyfus not only questioned the results they had so far obtained, but he also criticized their basic presupposition (that intelligence consists of the manipulation of physical symbols according to formal rules), and argued that the AI research program was doomed to failure. In 1965, he spent time at the Rand Corportation , whilst work on artificial intelligence was in progress there.
Dreyfus's critique of artificial intelligence (AI) concerns what he considers to be the four primary assumptions of AI research. The first two assumptions he criticizes are what he calls the "biological" and "psychological" assumptions. The biological assumption is that the brain is analogous to computer hardwareHardware is equipment such as fasteners, keys, locks, hinges, wire, chains, plumbing supples, tools, utensils, cutlery and machine parts, especially when they are made of metal. In the United States, hardware has been traditionally sold in " hardware stor and the mind is analagous to computer software. The psychological assumption is that the mind works by performing discrete computations (in the form of algorithmic rules) on discrete representationsIn cognitive psychology a representation is a hypothetical 'internal' 'cognitive' symbol that represents external reality. Representationalism (also known as indirect realism) is the view that representations are the main way we access external reality. or symbols.
Dreyfus claims that the plausibility of the psychological assumption rests on two others: the epistemologicalEpistemology is the branch of philosophy that deals with the nature, origin and scope of knowledge. Definition of knowledge Justified true belief Plato's Theaetetus''. defined knowledge as justified true belief. One implication of this definition is that and ontologicalThis article is about the philosophical meaning of ontology . For the term in computer science, see ontology (computer science). In philosophy, ontology is the most fundamental branch of metaphysics. It is the study of being or existence as well as the ba assumptions. The epistemological assumption is that all activity (either by animate or inanimate objects) can be formalised (mathematically) in the form of predictive rules or laws. The ontological assumption is that it is an objective fact that reality consists of a set of mutually independent, atomic (indivisible) facts (see fuzzy logicFuzzy logic is a superset of boolean logic dealing with the concept of partial truth''. Whereas classical logic holds that everything can be expressed in binary terms (0 or 1, black or white, yes or no), fuzzy logic replaces boolean truth values with degr). It's because of the epistemological assumption that workers in the field argue that intelligence is the same as formal rule-following, and it's because of the ontological one that they argue that humans use internal representations of reality. On the basis of these two assumptions, workers in the field claim that cognition is the manipulation of internal symbols by internal rules, and that, therefore, human behaviour is, to a large extent, context free (see contextualism). Therefore a truly scientific psychology is possible, which will detail the 'internal' rules of the human mind, in the same way the laws of physics detail the 'external' laws of the physical world. But it is this key assumption that Dreyfus denies. In other words, he argues that we cannot now (and never will) be able to understand our own behavior in the same way as we understand objects in, for example, physics or chemistry: that is, by considering ourselves as things whose behaviour can be predicted via 'objective', context free scientific laws. According to Dreyfus, a context free psychology is a contradiction in terms.
Dreyfus's arguments against for this position are taken from the phenomenological tradition (especially the work of Martin Heidegger). Heidegger argued that, contrary to the cognitivist views on which AI is based, our being is in fact highly context bound, which is why the two context-free assumptions are false. Dreyfus doesn't deny that we can choose to see human (or any) activity as being 'law governed', in the same way that we can choose to see reality as consisting of indivisible atomic facts...if we wish. But it is a huge leap from that to state that because we want to or can see things in this way that it is therefore an objective fact that they are the case. In fact, Dreyfus argues that they are not (necessarily) the case, and that, therefore, any research program that assumes they are will quickly run into profound theoretical and practical problems. Therefore the current efforts of workers in the field are doomed to failure. Given that Dreyfus has a reputation as a Luddite in some quarters, it's important to emphasise that he doesn't believe that AI is fundamentally impossible; only that the current research programme is fatally flawed. Instead he argues that to get a device (or devices) with human-like intelligence would require them to have a human-like being in the world, which would require them to have bodies more or less like ours, and social acculturation (i.e. a society) more or less like ours (this view is shared by psychologists in the embodied psychology and distributed cognition traditions: his opinions are also strangely similar to those of Rodney Brooks and others in the artificial life field).