There are theoretical limitations to what can be implemented by a computer program. In this paper we are concerned with a limitation on the strength of computer implemented deduction. We use a version of the Curry paradox to arrive at this limitation.

There is significant interest in type-free systems that allow flexible self-application. Such systems are of interest in property theory, natural language semantics, the theory of truth, theoretical computer science, the theory of classes, and category theory. While there are a variety of proposed type-free systems, there is a particularly natural type-free system that we believe is prototypical: the logic of recursive algorithms. Algorithmic logic is the study of basic statements concerning algorithms and the algorithmic rules of inference between such statements. (...) As shown in [1], the threat of paradoxes, such as the Curry paradox, requires care in implementing rules of inference in this context. As in any type-free logic, some traditional rules will fail. The first part of the paper develops a rich collection of inference rules that do not lead to paradox. The second part identifies traditional rules of logic that are paradoxical in algorithmic logic, and so should be viewed with suspicion in type-free logic generally. (shrink)

We develop a functional abstraction principle for the type-free algorithmic logic introduced in our earlier work. Our approach is based on the standard combinators but is supplemented by the novel use of evaluation trees. Then we show that the abstraction principle leads to a Curry fixed point, a statement C that asserts C ⇒ A where A is any given statement. When A is false, such a C yields a paradoxical situation. As discussed in our earlier work, this situation leaves (...) one no choice but to restrict the use of a certain class of implicational rules including modus ponens. (shrink)

α-recursion lifts classical recursion theory from the first transfinite ordinal ω to an arbitrary admissible ordinal α [10]. Idealized computational models for α-recursion analogous to Turing machine models for classical recursion have been proposed and studied [4] and [5] and are applicable in computational approaches to the foundations of logic and mathematics [8]. They also provide a natural setting for modeling extensions of the algorithmic logic described in [1] and [2]. On such models, an α-Turing machine can complete a θ-step (...) computation for any ordinal θ < α. Here we consider constraints on the physical realization of α-Turing machines that arise from the structure of physical spacetime. In particular, we show that an α-Turing machine is realizable in a spacetime constructed from R only if α is countable. While there are spacetimes where uncountable computations are possible and while they may even be empirically distinguishable from a standard spacetime, there is good reason to suppose that such nonstandard spacetimes are nonphysical. We conclude with a suggestion for a revision of Church’s thesis appropriate as an upper bound for physical computation. (shrink)

In this note, we consider constraints on the physical possibility of transfinite Turing machines that arise from how one models the continuous structure of space and time in one's best physical theories. We conclude by suggesting a version of Church's thesis appropriate as an upper bound for physical computation given how space and time are modeled on our current physical theories.

Brain mapping studies using dynamic imaging methods demonstrate areas regional cerebral blood flow (rCBF) decreases, as well as areas where increases, during performance of various experimental tasks. Task holds for both sets of cerebral blood flow changes (CBF), providing the opportunity to investigate areas that become and “activated” in the experimental condition relative to control state. Such data yield the intriguing observation that in areas in emotional processing, such as the amygdala, the posteromedial cortex, and the ventral anterior cingulate cortex, (...) although flow as expected during specific emotion-related tasks, flow decreases performance of some attentionally demanding, cognitive tasks. Conversely, in some of the areas that appear to subserve cognitive functions, as the dorsal anterior cingulate and the dorsolateral prefrontal cortices, increases while performing attentionally demanding cognitive tasks, but during some experimentally induced and pathological emotional Although the specific nature of such reciprocal patterns of regional remains unclear, they may reflect an important cross-modal interaction during mental operations. The possibility that neural activity is less in areas required in emotional processing during some higher cognitive processes holds implications for the mechanisms underlying interactions cognition and emotion. Furthermore, the possibility that neural in some cognitive-processing areas is suppressed during intense states suggests mechanisms by which extreme fear or severe may interfere with cognitive performance. (shrink)

Brain mapping studies using dynamic imaging methods demonstrate areas regional cerebral blood flow (rCBF) decreases, as well as areas where increases, during performance of various experimental tasks. Task holds for both sets of cerebral blood flow changes (CBF), providing the opportunity to investigate areas that become and “activated” in the experimental condition relative to control state. Such data yield the intriguing observation that in areas in emotional processing, such as the amygdala, the posteromedial cortex, and the ventral anterior cingulate cortex, (...) although flow as expected during specific emotion-related tasks, flow decreases performance of some attentionally demanding, cognitive tasks. Conversely, in some of the areas that appear to subserve cognitive functions, as the dorsal anterior cingulate and the dorsolateral prefrontal cortices, increases while performing attentionally demanding cognitive tasks, but during some experimentally induced and pathological emotional Although the specific nature of such reciprocal patterns of regional remains unclear, they may reflect an important cross-modal interaction during mental operations. The possibility that neural activity is less in areas required in emotional processing during some higher cognitive processes holds implications for the mechanisms underlying interactions cognition and emotion. Furthermore, the possibility that neural in some cognitive-processing areas is suppressed during intense states suggests mechanisms by which extreme fear or severe may interfere with cognitive performance. (shrink)

This chapter contains section titled: Husserl's Cartesianism Heidegger's Ontological Critique References and Further Reading.

I review Adrian Moore’s lucid account of Fichte’s contribution to the Evolution of Modern Metaphysics. I support Moore’s contention that Fichte should indeed be considered a metaphysician, but I propose an adjustment to Moore’s interpretation, guided by Fichte’s own claim that the infinite I is an unattainable ideal, rather than a fact about the constitution of reality as it actually is. The resulting position embeds Fichte’s metaphysics firmly within his ethics and politics. In reconstructing Fichte’s position I demonstrate the centrality (...) of work in Fichte’s proposed resolution of Kant’s third antinomy. (shrink)

If one believes that the brain is, in some as yet unspecified way, the organ of mind and behaviour, then all human behaviour has a neurobiological basis. Neuroscience research over the past several decades has provided more specific reasons for believing that many addictive phenomena have a neurobiological basis. The major psychoactive drugs of dependence have been shown to act on neurotransmitter systems in the brain (Nutt 1997; Koob 2000); common neurochemical mechanisms underlie many of the rewarding effects of these (...) drugs and the phenomena of tolerance and withdrawal symptoms (Hyman & Malenka 2001; Koob 2000), and there is evidence for a genetic vulnerability to addiction (Nestler 2001; Uhl 1999) that is mediated by genes that regulate the metabolism of psychoactive drugs and the brain neurotransmitter systems on which they act (Uhl 1999). (shrink)

Some well-known translations of the words attributed to the Master in Analects 6.25, "gu bu gu gu zai gu zai," are analyzed and sorted out. It is argued that this passage can be given a consistent reading and an interpretation that coheres with a major theme of the text, namely that the ontological status of a thing, like that of a person, is relative to the practice of constitutive rules and conventions.

A comprehensive political philosophy, arguing for Christian involvement based on biblical teachings and a Christian worldview. --from publisher description.

Australia does not allow adult smokers to buy or use electronic nicotine delivery systems that contain nicotine without a prescription. This paper critically evaluates the empirical and ethical justifications provided for the policy by Federal and State governments, public health advocates and health organisations. These are: that ENDS should only be approved as products for smoking cessation when there is evidence from randomised controlled trials that they are effective; that as a matter of precaution we should not allow the sale (...) of ENDS to smokers as consumer products because we do not know what their long-term effects will be; and that allowing ENDS to be sold as consumer goods will enable the tobacco industry to market ENDS to young people which will also lead to an increase in youth smoking. We show that the arguments and evidence offered in support of all these claims is very weak. We also argue that even if the evidence were stronger, it would not justify denying adult smokers the right to use ENDS either to quit smoking or as a long-term alternative to smoking cigarettes. We outline ENDS policies that would more ethically address the public health concerns that motivated the current policy by allowing adult smokers to access ENDS for smoking cessation or tobacco harm reduction under tight regulations that discourage commercial promotion and adolescent use. (shrink)

Aquinas contradicts Isaiah VI. 6 because of his following of the ps. Dionysius, who is in turn reproducing the logical structures of Iamblichus and Proclus. These came to prevail despite doubts raised by earlier medieval theologians with the exception of Eriugena. Here are considered Thomas’ principles of biblical interpretation and the character of his Aristotelianism. His thought is shown to be a form of neoplatonic systematizing as developed by Iamblichus and Proclus.

A Daoist Theory of Chinese Thought Chad Hansen, 1992 New York; Oxford University Press xvi + 448 pp., hb $65.00.

The East Asian Region: Confucian Heritage And Its Modern Adaptation. Gilbert Rozman, 1990 Princeton, NJ, Princeton University Press, 1990 v?x + 235 pp., $29.95.

In lieu of an abstract, here is a brief excerpt of the content:BOOK REVIEWS 693 between the world of our sense perception and the world of objects "in and for themselves," had suggested that the failure to appreciate this distinction was a "Grundvorurteil" common to all controversies, and, finally, had argued for the need to distinguish between the self revealed in "inner sense" and the self as it is in itself, unknowable to us. In his extremely valuable article, "Funzioni logiche (...) e categorie in Kant," Silvestro Marcucci retlects on a complex of issues surrounding Kant's claim to have discovered some sort of correspondence between the components and structure of a "table" of logical functions and those of a set of"pure concepts" or "categories" for the objective determination of objects through the contents of human sensibility. Of central concern to Marcucci is the error of supposing that what is in question is either a mere parallel between functions of judgment and categories or some sort of real identity between them. What is in question, according to Marcucci, are three "uses" but only two "levels" (piani): the foundational level is that of an operative.judgmental "functionality" by which the categories and the pure forms of general logic are produced. He argues that Kant is appealing here neither to pure logical form nor to logical "functions" that are in some way identical with the categories of understanding, but rather to functions of judgment more fundamental than either. The final two essays deal with two of Kant's immediate heirs, Reinhold and Fichte. In "The Sun of Enlightenment" Nathan Rotenstreich argues that Reinhold's notion of Enlightenment had an important social aspect, which is concerned with the distribution of enlightenment and is distinguished from his systematic view. Claudio Cesa, in "Die Vieldeutigkeit des Begriffes 'Trieb' von J. G. Fichte" traces the development of this important concept from Reinhold's concept "Kraft," which was itself neither sensible nor intellectual but changed depending upon its objects: sensibility, understanding, or reason. Cesa goes on to outline how Fichte developed a more positive notion including the conception of inner purposiveness expressing itself in humans as a form for realizing the I. JANE KNELI.ER Colorado State University RICHARD AQUILA University of Tennessee George J. Seidel. Fichte's "Wissenschaftslehre" of z 794: A Commentary on Part I. Purdue University Series in the History of Philosophy. West Lafayette, IN: Purdue University Press, 1993. Pp. ix + 126. Cloth, $25.00. Paper, $12.95. The recent revival of interest in Fichte is now well entrenched in North America and has begun to yield a fairly diverse harvest: new translations, articles, monographs, and, predictably, conferences and a scholarly society. With this volume, however, we have the first entry in the "commentary" category. Given its notorious obscurity and disarray, Fichte's corpus--particularly his Jena corpus, which has remained the main focus of attention--would seem to be an apt subject for the genre. The work to which Seidel has 694 JOURNAL OF THE HISTORY OF PHILOSOPHY 33:4 OCTOBER ~995 devoted his attention--the Foundations of the Entire "Wissenschaft~lehre"--particularly invites this sort of undertaking; it is a text which, by Fichte's own account, was intended to be accompanied by elaborations, illustrations and explanations. Seidel focuses on what is certainly the most interesting and important part of the text, the first three sections (about 3~ pages in all) which together make up "Part I" of this version of the Wissenschaftslehre. It is here that Fichte tries to articulate the basic principles that will govern his entire philosophical investigation. He uses as the lever for his enquiry two fundamental logical dicta--the principles of identity and contradiction--claiming to uncover three fundamental principles which underlie them: the principles of selfpositing, counter-positing and limitation. The body of the Wissenschaflslehreitself is an elaborate dialectical attempt to work out the implications of these basic features of human subjectivity--in particular to use them to give a deduction of the fundamental categories of human experience. There are a number of different approaches that a commentary might take to this dense piece of text. At one extreme stands the example provided by Findlay, whose commentary on Hegel's Phenomenology takes the form of a detailed paraphrase... (shrink)

In a well-known passage from the Analytic of the second Critique, Kant makes reference to what he calls “an unavoidable need of human reason”—the need to find “the unity of the entire pure faculty of reason.” The remark is made in passing, and Kant himself deals only obliquely with the question as to how this need might be met. Indeed, two centuries later we may be inclined to say that Kant’s legacy was less to unite theoretical and practical reason than (...) to sunder them—relegating them to the distinct philosophical subdisciplines that have become an institutional fact of life. For Kant’s most controversial disciple, however, satisfying this “unavoidable need” was to become something of a philosophical obsession. From his earliest forays in systematic philosophy we see J. G. Fichte determined to uncover the deep unity of rational human subjectivity and thereby to exhibit the unity of theoretical and practical reason. (shrink)

As more wind energy projects are constructed and placed into operation, their potential downsides are becoming more apparent to a larger number of people. One of the most contentious issues is that of the potential loss of property values for those who happen to own homes close to these projects. This issue may be more parochial and therefore seemingly less important than larger global issues, such as energy independence, sustainability, or global warming. But for those most directly affected by these (...) projects, it can serve as a single proxy for all the other local concerns with wind turbines, such as noise, visual pollution, and health. Moreover, rural homeowners vote in high numbers, and in those locations where there is still local control of wind energy projects, the local politicians will eventually reflect those concerns. The wind energy industry counters these concerns by quoting from a series of industry and government studies that claim to show that proximity to wind turbines does not materially affect home prices. However, their efforts at allaying the concerns of the local homeowners have not been very successful. This article discusses some of the reasons why the industry has been unsuccessful at quelling these concerns, including an evaluation of the evidence from both sides of the wind energy debate as a homeowner might see it and ends with suggestions on how the industry might allay these concerns. (shrink)

This philosophical treatise on the foundations of semantics is a systematic effort to clarify, deepen, and defend the classical doctrine that words are conventional signs of mental states, principally thoughts and ideas, and that meaning consists in their expression. This expression theory of meaning is developed by carrying out the Gricean program, explaining what it is for words to have meaning in terms of speaker meaning, and what it is for a speaker to mean something in terms of intention. But (...) Grice's own formulations are rejected and alternatives developed. The foundations of the expression theory are explored at length, and the author develops the theory of thought as a fundamental cognitive phenomenon distinct from belief and desire, argues for the thesis that thoughts have parts, and identifies ideas or concepts with parts of thoughts. This book will appeal to students and professionals interested in the philosophy of language. (shrink)

This paper considers the connection between automaticity, control and agency. Indeed, recent philosophical and psychological works play up the incompatibility of automaticity and agency. Specifically, there is a threat of automaticity, for automaticity eliminates agency. Such conclusions stem from a tension between two thoughts: that automaticity pervades agency and yet automaticity rules out control. I provide an analysis of the notions of automaticity and control that maintains a simple connection: automaticity entails the absence of control. An appropriate analysis, however, shows (...) that actions are forms of control and pervasively automatic even if automaticity implies the absence of control. Consequences are drawn for the theory of mental agency and the psychological concepts of automaticity and control. (shrink)