A Critique of Artificial Reason Hubert L. Dreyfus . HUBERT L. DREYFUS What Computers Still Can't Do Thi s One XZKQ-GSY-8KDG What. WHAT COMPUTERS STILL CAN'T DO Front Cover.

The original proof of the four-color theorem by Appel and Haken sparked a controversy when Tymoczko used it to argue that the justification provided by unsurveyable proofs carried out by computers cannot be a priori. It also created a lingering impression to the effect that such proofs depend heavily for their soundness on large amounts of computation-intensive custom-built software. Contra Tymoczko, we argue that the justification provided by certain computerized mathematical proofs is not fundamentally different from that provided by (...) surveyable proofs, and can be sensibly regarded as a priori. We also show that the aforementioned impression is mistaken because it fails to distinguish between proof search (the context of discovery) and proof checking (the context of justification). By using mechanized proof assistants capable of producing certificates that can be independently checked, it is possible to carry out complex proofs without the need to trust arbitrary custom-written code. We only need to trust one fixed, small, and simple piece of software: the proof checker. This is not only possible in principle, but is in fact becoming a viable methodology for performing complicated mathematical reasoning. This is evinced by a new proof of the four-color theorem that appeared in 2005, and which was developed and checked in its entirety by a mechanical proof system. (shrink)

One recursively enumerable real α dominates another one β if there are nondecreasing recursive sequences of rational numbers (a[n] : n ∈ ω) approximating α and (b[n] : n ∈ ω) approximating β and a positive constant C such that for all n, C(α − a[n]) ≥ (β − b[n]). See [R. M. Solovay, Draft of a Paper (or Series of Papers) on Chaitin’s Work, manuscript, IBM Thomas J. Watson Research Center, Yorktown Heights, NY, 1974, p. 215] and [G. J. (...) Chaitin, IBM J. Res. Develop., 21 (1977), pp. 350–359]. We show that every recursively enumerable random real dominates all other recursively enumerable reals. We conclude that the recursively enumerable random reals are exactly the Ω-numbers [G. J. Chaitin, IBM J. Res. Develop., 21 (1977), pp. 350–359]. Second, we show that the sets in a universal Martin-Lof test for randomness have random measure, and every recursively enumerable random number is the sum of the measures represented in a universal Martin-Lof test. (shrink)

How did life come into existence on Earth? Although many scientific theories and hypotheses have been drawn, we have not yet been able to provide a detailed answer to this fundamental question. What if intelligent computers would someday be in a condition to postulate their own evolution theory which would explain how they came into the world, how would this theory look like? And how would it stand in comparison to the humans’ theory? Let us suppose that a thousand (...) years from now, intelligent and self-aware computers who, for any reason whatsoever, had lost all contacts with humans, and had continued to self-develop and improve by themselves, slowly began to wonder about how they came into the world? These intelligent computers may eventually develop a coherent theory of evolution, which would seemingly explain their existence. How would their theory stand in comparison to our theory of evolution? Would it be less comprehensive or viable? Taking into consideration the inorganic nature of computers, their relative simplicity compared to the human body, and the closeness of their components to the surrounding inorganic environment, it would not be a surprise if their theory would be more plausible than that of the humans. So, what would this signify and mean to our scientific theories in general? (shrink)

This book constitutes the strictly refereed post-workshop proceedings of the 11th International Workshop on Computer Science Logic, CSL '97, held as the 1997 Annual Conference of the European Association on Computer Science Logic, EACSL, in Aarhus, Denmark, in August 1997. The volume presents 26 revised full papers selected after two rounds of refereeing from initially 92 submissions; also included are four invited papers. The book addresses all current aspects of computer science logics and its applications and thus presents the state (...) of the art in the area. (shrink)

In Section 2, I survey some of the ways that computers are used in mathematics. These raise questions that seem to have a generally epistemological character, although they do not fall squarely under a traditional philosophical purview. The goal of this article is to try to articulate some of these questions more clearly, and assess the philosophical methods that may be brought to bear. In Section 3, I note that most of the issues can be classified under two headings: (...) some deal with the ability of computers to deliver appropriate “evidence” for mathematical assertions, a notion that is explored in Section 4, while others deal with the ability of computers to deliver appropriate mathematical “understanding,” a notion that is considered in Section 5. Final thoughts are provided in Section 6. (shrink)

I offer an explication of the notion of computer, grounded in the practices of computability theorists and computer scientists. I begin by explaining what distinguishes computers from calculators. Then, I offer a systematic taxonomy of kinds of computer, including hard-wired versus programmable, general-purpose versus special-purpose, analog versus digital, and serial versus parallel, giving explicit criteria for each kind. My account is mechanistic: which class a system belongs in, and which functions are computable by which system, depends on the system's (...) mechanistic properties. Finally, I briefly illustrate how my account sheds light on some issues in the history and philosophy of computing as well as the philosophy of mind. (shrink)

A true Turing machine (TM) requires an infinitely long paper tape. Thus a TM can be housed in the infinite world of Newtonian spacetime (the spacetime of common sense), but not necessarily in our world, because our world-at least according to our best spacetime theory, general relativity-may be finite. All the same, one can argue for the "existence" of a TM on the basis that there is no such housing problem in some other relativistic worlds that are similar ("close") to (...) our world. But curiously enough-and this is the main point of this paper-some of these close worlds have a special spacetime structure that allows TMs to perform certain Turing unsolvable tasks. For example, in one kind of spacetime a TM can be used to solve first-order predicate logic and the halting problem. And in a more complicated spacetime, TMs can be used to decide arithmetic. These new computers serve to show that Church's thesis is a thoroughly contingent claim. Moreover, since these new computers share the fundamental properties of a TM in ordinary operation (e.g. intuitive, finitely programmed, limited in computational capability), a computability theory based on these non-Turing computers is no less worthy of investigation than orthodox computability theory. Some ideas about this new mathematical theory are given. (shrink)

Recent work on hypercomputation has raised new objections against the Church–Turing Thesis. In this paper, I focus on the challenge posed by a particular kind of hypercomputer, namely, SAD computers. I first consider deterministic and probabilistic barriers to the physical possibility of SAD computation. These suggest several ways to defend a Physical version of the Church–Turing Thesis. I then argue against Hogarth's analogy between non-Turing computability and non-Euclidean geometry, showing that it is a non-sequitur. I conclude that the Effective (...) version of the Church–Turing Thesis is unaffected by SAD computation. (shrink)

In Computers Ltd, David Harel, best-selling author of Algorithmics, explains and illustrates one of the most fundamental, yet under-exposed facets of computers - their inherent limitations. Looking at the bad news that is proven, lasting, and robust, discussing limitations that no amounts of hardware, software, talents, or resources can overcome, the book presents a disturbing and provocative view of computing at the start of the 21st century.

This article disrupts the logic of the “just-a-tool” argument, a powerful rhetorical device commonly offered as a rationale for using computers in education (and health care and other areas of society). Although this argument is articulated in many ways, its essence is the contention that computers are merely instructional tools, like blackboards or pencils, that can be used to enhance learning and therefore should be used in classrooms. The just-a-tool argument is difficult to challenge because it automatically constructs (...) counterarguments as illogical; they necessarily become arguments against using technology to improve the human condition. However, an analysis of the just-a-tool argument reveals that far from being logical and unassailable, it is both invalid and unsound. This “techno-illogic,” as the author calls it, arises when wisdom is subjugated to the dictates of technological “rationality,” and it is something that people must learn to recognize and defend against. (shrink)

Presented here is a new result concerning the computational power of so-called SADn computers, a class of Turing-machine-based computers that can perform some non-Turing computable feats by utilising the geometry of a particular kind of general relativistic spacetime. It is shown that SADn can decide n-quantifier arithmetic but not (n+1)-quantifier arithmetic, a result that reveals how neatly the SADn family maps into the Kleene arithmetical hierarchy. Introduction Axiomatising computers The power of SAD computers Remarks regarding the (...) concept of computability. (shrink)

The distinction at the heart of van Gelder’s target article is one between digital computers and dynamical systems. But this distinction conflates two more fundamental distinctions in cognitive science that should be keep apart. When this conflation is undone, it becomes apparent that the “computational hypothesis” (CH) is not as dominant in contemporary cognitive science as van Gelder contends; nor has the “dynamical hypothesis” (DH) been neglected.

There has been much debate whether computers can be responsible. This question is usually discussed in terms of personhood and personal characteristics, which a computer may or may not possess. If a computer fulfils the conditions required for agency or personhood, then it can be responsible; otherwise not. This paper suggests a different approach. An analysis of the concept of responsibility shows that it is a social construct of ascription which is only viable in certain social contexts and which (...) serves particular social aims. If this is the main aspect of responsibility then the question whether computers can be responsible no longer hinges on the difficult problem of agency but on the possibly simpler question whether responsibility ascriptions to computers can fulfil social goals. The suggested solution to the question whether computers can be subjects of responsibility is the introduction of a new concept, called “quasi-responsibility” which will emphasise the social aim of responsibility ascription and which can be applied to computers. (shrink)

Computational neuroscientists not only employ computer models and simulations in studying brain functions. They also view the modeled nervous system itself as computing. What does it mean to say that the brain computes? And what is the utility of the ‘brain-as-computer’ assumption in studying brain functions? In previous work, I have argued that a structural conception of computation is not adequate to address these questions. Here I outline an alternative conception of computation, which I call the analog-model. The term ‘analog-model’ (...) does not mean continuous, non-discrete or non-digital. It means that the functional performance of the system simulates mathematical relations in some other system, between what is being represented. The brain-as-computer view is invoked to demonstrate that the internal cellular activity is appropriate for the pertinent information-processing task.Keywords: Computation; Computational neuroscience; Analog computers; Representation; Simulation. (shrink)

Why do the big philosophical questions so often strike us as far-fetched and little to with everyday life? Mary Midgley shows that it need not be that way; she shows that there is a need for philosophy in the real world. Her popularity as one of our foremost philosophers is based on a no-nonsense, down-to-earth approach to fundamental human problems, philosphical or otherwise. In _Utopias, Dolphins and Computers_ she makes her case for philosophy as a difficult but necessary tool for (...) solving some of the most pressing issues facing contemporary society. How should we treat animals? Why are we so confused about the value of education? What is at stake in feminism? Why should we sustain our environment? Why do we think intelligent computers will save us? Mary Midgley argues that philosophy not only can, but should be used in thinking about these questions. _Utopias, Dolphins and Computers_ will make fascinating reading for philosophers, educationalists, feminists, environmentalists and indeed anyone interested in the questions of philosophy, ethics and life. (shrink)

Within psychiatric research, the field of 'technotherapy' has been centred primarily on attempts to assess the computer as a treatment tool. The situation of daily clinical usage is, however, often ignored within such research, as for instance in controlled clinical trials. Our empirical study illustrates how health professionals and clients use different concepts of science and health in the attempts of formulating standards for using computers in psychiatric practice. The psychiatrists at a major psychiatric hospital decided and justified clients' (...) use of computers on the basis of a 'techno-medical' quality assurance. At the same hospital the occupational therapists stressed the improvement of social relations as a treatment goal. And, at a psychiatric outside clinic the clients used concepts of 'normality' for articulating quality in computer use. Our study exemplifies how the use of computers is a multifaceted 'performance'. What is called for is a kind of research not limited by artificial borders of 'the context' and the 'user-perspective'. In much humanistic research as well as in action research concepts of 'context' and 'user-perspective' imply a somehow romantic view on practice as pure and uncontaminated by the outside world contrasted to a 'general' or an 'objective' way of knowing the world. These sharp distinctions were however difficult to maintain in our study, where health professionals and clients took local contingencies into account when they interpreted computer use, while they simultaneously drew on a socio-historical reservoir of resources. (shrink)

The federal and corporate initiative to technologize education has transformed schools, colleges, and universities into a new frontier for the computer industry. While educational institutions have maintained an equivocal relationship with markets and the state, they had striven to preserve a simulacrum of independence until the early 1980s. Then, neoconservative ideologies and their accompanying discourse on restructuring education discovered in the computer the ideal neutral tool to promote, in its virtual clothes, their gospel. The Clinton administration and big corporations, taking (...) advantage of the myth of the computer and the new vocabulary associated with computers, launched a massive program of wiring schools. The process, still unfolding at a rapid pace, poses grave problems for the teaching profession and the role of schools in society. The author argues that the unethical ways in which computers force their ways into many educational institutions, the values they embody, the contexts of their multiple usages, the hyperfragmentation and increasing commodification of knowledge that they cause through online education, the vocationalization of education, and the atomization of teachers are likely to shrink pedagogical and democratic possibilities both at local and global levels. (shrink)

This paper examines the use of tablet personal computers and how they interfere with Nigerian undergraduates reading culture and love for educational books. The study adopts a descriptive research design. The University of Ilorin undergraduates constitute the population for this study while 200 level students of three faculties across the university constitute the target population. Stratified sampling technique was used to sample the needed respondents. A researchers’ designed questionnaire was use for data collection. The collected data was analysed using (...) descriptive statistics. The findings revealed that access to tablet computer influence the undergraduate reading culture. Also, 55.7% of 200 level undergraduates read more electronic materials on their tablet computer than printed texts. Based on the findings of this study, it is recommended that students should be encouraged to visit the library and read textbooks since there is certain fundamental knowledge that might not be accessible on the net. (shrink)

Quantum physics is a linear theory, so it is somewhat puzzling that it can underlie very complex systems such as digital computers and life. This paper investigates how this is possible. Physically, such complex systems are necessarily modular hierarchical structures, with a number of key features. Firstly, they cannot be described by a single wave function: only local wave functions can exist, rather than a single wave function for a living cell, a cat, or a brain. Secondly, the quantum (...) to classical transition is characterised by contextual wave-function collapse shaped by macroscopic elements that can be described classically. Thirdly, downward causation occurs in the physical hierarchy in two key ways: by the downward influence of time dependent constraints, and by creation, modification, or deletion of lower level elements. Fourthly, there are also logical modular hierarchical structures supported by the physical ones, such as algorithms and computer programs, They are able to support arbitrary logical operations, which can influence physical outcomes as in computer aided design and 3-d printing. Finally, complex systems are necessarily open systems, with heat baths playing a key role in their dynamics and providing local arrows of time that agree with the cosmological direction of time that is established by the evolution of the universe. (shrink)

From the late 1960s to the early 1980s, a team of U.S. political scientists and computer specialists designed an automated, computerized information system that could ostensibly forecast conflict earlier and more accurately than human analysts. Named the Crisis Early Warning and Monitoring System (EWAMS), it sought to bring international relations scholarship and U.S. national security policy—traditionally qualitative and interpretive domains—under the jurisdiction of a man–machine system. Drawing together the histories of social science, computing, and foreign policy, this essay argues that (...) deep epistemic insecurities led social scientists to apply information technology to the production of policy knowledge. Computers, they hoped, could overcome the innate cognitive limitations that imperiled human decision making. By showing how social scientists’ computational zeal overshadowed their commitment to human agency, this essay also demonstrates that the history of science has an important role to play in contemporary debates about the implications of big data projects for knowledge and policy. (shrink)

In modern technical societies computers interact with human beings in ways that can affect moral rights and obligations. This has given rise to the question whether computers can act as autonomous moral agents. The answer to this question depends on many explicit and implicit definitions that touch on different philosophical areas such as anthropology and metaphysics. The approach chosen in this paper centres on the concept of information. Information is a multi-facetted notion which is hard to define comprehensively. (...) However, the frequently used definition of information as data endowed with meaning can promote our understanding. It is argued that information in this sense is a necessary condition of cognitivist ethics. This is the basis for analysing computers and information processors regarding their status as possible moral agents. Computers have several characteristics that are desirable for moral agents. However, computers in their current form are unable to capture the meaning of information and therefore fail to reflect morality in anything but a most basic sense of the term. This shortcoming is discussed using the example of the Moral Turing Test. The paper ends with a consideration of which conditions computers would have to fulfil in order to be able to use information in such a way as to render them capable of acting morally and reflecting ethically. (shrink)