In his book Shadows of the Mind: A search for the missing science of con- sciousness [SM below], Roger Penrose has turned in another bravura perfor- mance, the kind we have come to expect ever since The Emperor’s New Mind [ENM ] appeared. In the service of advancing his deep convictions and daring conjectures about the nature of human thought and consciousness, Penrose has once more drawn a wide swath through such topics as logic, computa- tion, artificial intelligence, quantum (...) physics and the neuro-physiology of the brain, and has produced along the way many gems of exposition of difficult mathematical and scientific ideas, without condescension, yet which should be broadly appealing. 1 While the aims and a number of the topics in SM are the same as in ENM, the focus now is much more on the two axes that Pen- rose grinds in earnest. Namely, in the first part of SM he argues anew and at great length against computational models of the mind and more specifi- cally against any account of mathematical thought in computational terms. Then in the second part, he argues that there must be a scientific account of consciousness but that will require a (still to be found) non-computational extension or modification of present-day quantum physics. (shrink)

[opening paragraph]: As some of us in the brain and cognitive sciences struggled in relative obscurity over the last two decades to gain some sound empirical understanding of conscious experience, a succession of celebrated philosophers and scientists told us that our work was doomed to failure. They expended extraordinary ingenuity trying to prove their case, at least as much as those of us toiling in the trenches devoted to the job of gaining a little bit of clarity. Fortunately, `impossibility proofs' (...) of this kind tend to have a short half-life. They succeed each other year after year; in the same way that impossibility proofs were flourished triumphantly by critics to demonstrate, once and forever, that we could never understand planetary motion, biological evolution, quantum mechanics -- or whatever next topic science, in its Brobdignagian march, was threatening to clarify. Arthur C. Clarke once proposed a law stating that for every major advance in knowledge one can find at least one celebrated scientist who was able to `prove', shortly before it was achieved, that it could not be done. In the case of conscious experience the quest to prove impossibility is especially passionate, as if a reasonable scientific approach to human experience were the enemy of all that is good and decent. (shrink)

Where does the road to reality lie? This fundamental question is addressed in this collection of essays by physicists and philosophers, inspired by the original ideas of Sir Roger Penrose, the English mathematical physicist and philosopher of science. The topics range from black holes and quantum information to the very nature of mathematical cognition itself. *** Librarians: ebook available on ProQuest and EBSCO [Subject: Philosophy, Physics, Mathematics, Cosmology].

Summarizing a surrounding 200 pages, pages 179 to 190 of Shadows of the Mind contain a future dialog between a human identified as "Albert Imperator" and an advanced robot, the "Mathematically Justified Cybersystem", allegedly Albert's creation. The two have been discussing a Gödel sentence for an algorithm by which a robot society named SMIRC certifies mathematical proofs. The sentence, referred to in mathematical notation as Omega(Q*), is to be precisely constructed from on a definition of SMIRC's algorithm. It can be (...) interpreted as stating "SMIRC's algorithm cannot certify this statement." The robot has asserted that SMIRC never makes mistakes. If so, SMIRC's algorithm cannot certify the Goedel sentence, for that would make the statement false. But, if they can't certify it, what is says is true! Humans can understand it is true, but mighty SMIRC cannot certify it. The dialog ends melodramatically as the robot, apparently unhinged by this revelation, claims to be a messenger of god, and the human shuts it down with a secret control. (shrink)

A talk delivered at the conference “Science and Religion: The Religious Beliefs and Practices of Scientists—20th Century,” Institut für Wissenschaftsgeschichte, Georg-August-Universität, Göttingen, 28 May 2002.

Al final de su libro “La conciencia inexplicada”, Juan Arana señala que la nomología, explicación según las leyes de la naturaleza, requiere de una nomogonía, una consideración del origen de las leyes. Es decir, que el orden que observamos en el mundo natural requiere una instancia previa que ponga ese orden específico. Sabemos que desde la revolución científica la mejor manera de explicar dicha nomología ha sido mediante las matemáticas. Sin embargo, en las últimas décadas se han presentado algunas propuestas (...) basadas en modelos matemáticos que fundamentarían muchos aspectos de la realidad. Dos claros ejemplos provienen de Roger Penrose y Max Tegmark. Esto lleva a pensar en una posición no solo nomológica sino además nomogónica de la matemática. ¿Puede la Naturaleza estar fundada por las matemáticas como señalan algunos físico-matemáticos? Y en ese caso, ¿sería pertinente buscar una nomo-génesis de esta índole en la constitución de la conciencia? -/- At the end of his book “La conciencia inexplicada”, Juan Arana points out that nomology, explanation according to the laws of nature requires a nomogony, an account of the origin of the laws. This means that the order that we can observe in the natural World demands something prior to posit that specific order. Since the scientific revolution we know that the best way to explain that nomology has been through mathematics. Anyway, in recent decades a number of proposals based on mathematical models that found many aspects of reality has been offered. Two clear examples come from Roger Penrose and Max Tegmark. This drives us to think of a position of mathematics as not only nomological but also nomogonical. Can Nature be founded by mathematics as some physicists and mathematicians point out? And, in this case, would be relevant this kind of approach to search a nomo-genesis in the constitution of consciousness? (shrink)

Roger Penrose is known for his proposals, in collaboration with Stuart Hameroff, for quantum action in the brain. These proposals, which are still recent, have a prior, less known basis, which will be studied in the following work. First, the paper situates the framework from which a mathematical physicist like Penrose proposes to speak about consciousness. Then it shows how he understands the possible relationships between computation and consciousness and what criticism from other authors he endorses, to conclude by (...) explaining how he understands this relationship between consciousness and computation. Then, it focuses on the concept of non-locality so essential to his understanding of consciousness. With some examples, such as impossible objects or aperiodic tiling, the study addresses the concept of non-locality as Penrose understands it, and then shows how far he intends to arrive with that concept of non-locality. At all times the approach will be more philosophical than physical. (shrink)

Roger Penrose is known for his proposals, in collaboration with Stuart Hameroff, for quantum action in the brain. These proposals, which are still recent, have a prior, less known basis, which will be studied in the following work. First, the paper situates the framework from which a mathematical physicist like Penrose proposes to speak about consciousness. Then it shows how he understands the possible relationships between computation and consciousness and what criticism from other authors he endorses, to conclude by (...) explaining how he understands this relationship between consciousness and computation. Then, it focuses on the concept of non-locality so essential to his understanding of consciousness. With some examples, such as impossible objects or aperiodic tiling, the study addresses the concept of non-locality as Penrose understands it, and then shows how far he intends to arrive with that concept of non-locality. At all times the approach will be more philosophical than physical. (shrink)

"The Emperor's New Mind" by Roger Penrose has received a great deal of both praise and criticism. This review discusses philosophical aspects of the book that form an attack on the "strong" AI thesis. Eight different versions of this thesis are distinguished, and sources of ambiguity diagnosed, including different requirements for relationships between program and behaviour. Excessively strong versions attacked by Penrose (and Searle) are not worth defending or attacking, whereas weaker versions remain problematic. Penrose (like Searle) regards the (...) notion of an algorithm as central to AI, whereas it is argued here that for the purpose of explaining mental capabilities the architecture of an intelligent system is more important than the concept of an algorithm, using the premise that what makes something intelligent is not what it does but how it does it. What needs to be explained is also unclear: Penrose thinks we all know what consciousness is and claims that the ability to judge Go "del's formula to be true depends on it. He also suggests that quantum phenomena underly consciousness. This is rebutted by arguing that our existing concept of "consciousness" is too vague and muddled to be of use in science. This and related concepts will gradually be replaced by a more powerful theory-based taxonomy of types of mental states and processes. The central argument offered by Penrose against the strong AI thesis depends on a tempting but unjustified interpretation of Goedel's incompleteness theorem. Some critics are shown to have missed the point of his argument. A stronger criticism is mounted, and the relevance of mathematical Platonism analysed. Architectural requirements for intelligence are discussed and differences between serial and parallel implementations analysed. (shrink)

In his stimulating book SHADOWS OF THE MIND, Roger Penrose presents arguments, based on Gödel's theorem, for the conclusion that human thought is uncomputable. There are actually two separate arguments in Penrose's book. The second has been widely ignored, but seems to me to be much more interesting and novel than the first. I will address both forms of the argument in some detail. Toward the end, I will also comment on Penrose's proposals for a "new science of consciousness".

The aim of the presented article is to provide an in-depth analysis of the adequacy of designating Penrose as a complex Pythagorean in view of his much more common designation as a Platonist. Firstly, the original doctrine of the Pythagoreans will be briefly surveyed with the special emphasis on the relation between the doctrine of this school and the teachings of the late Platonic School as well as its further modifications. These modifications serve as the prototype of the contemporary claims (...) of the mathematicity of the Universe. Secondly, two lines of Penrose’s arguments in support of his unique position on the ontology of the mathematical structures will be presented: their existence independent of the physical world in the atemporal Platonic realm of pure mathematics and the mathematical structures as the patterns governing the workings of the physical Universe. In the third step, a separate line of arguments will be surveyed that Penrose advances in support of the thesis that the complex numbers seem to suit these patterns with exceptional adequacy. Finally, the appropriateness of designation Penrose as a complex Pythagorean will be assessed with the special emphasis on the suddle threshold between his unique position and that of the adherents of the mathematicity of the Universe. (shrink)

This paper presents an analysis and critique of Roger Penrose’s epistemological, methodological, and ontological positions. The analysis is relevant not only because Penrose is an influential scientist, but also because of the particular traits of his thought. These traits are directly connected with his background and approach to science: ontological and epistemological realism, mathematical Platonism, emphasis on the continuities of science, epistemological inclusiveness and essential openness of science, the role of common sense, emphasis on the connection between science, ethics, (...) and philosophy. The paper articulates Penrose’s position and criticizes some of its possible shortcomings. It contributes to the perception of science as an open activity, as illustrated in Penrose’s particular approach, and provides an interesting case-study that can contribute to understanding how epistemological and ontological positions are connected with particular scientific practices. (shrink)

The modeling of the human mind based on quantum effects has been gaining considerable interest due to the intriguing possibility of applying non-local interactions in the studies of consciousness. Inasmuch as the majority of the pertinent studies are restricted to the exclusive analysis of mental phenomena, the quantum model of mind proposed by Roger Penrose constitutes a part of a much larger scheme of the ultimate unification of physics. Penrose's efforts to find the 'missing science of consciousness' presuppose the (...) non-algorithmic character of human thinking inferred from Gödel's incompleteness theorem. This is supposed to combine with the anticipated non-algorithmic character of the future quantum gravity theory involving the objective reduction of a quantum mechanical state vector. By surveying contemporary achievements of cognitive sciences as well as the development of Penrose's conjectures, presented in his recent work The Road to Reality, we wish to show that his non-algorithmic quantum model of human mind is contingent upon the fundamental philosophical assumption of the mathematicity of the Universe. (shrink)

In his latest book,Roger Penrose deals with three foundational problems of current physics fromhis particularly fresh perspective.He criticizes mainstream string the- ories, standard interpretations of quantum mechanics, and pre-Big Bang cosmolo- gies inasmuch as they aim to solve profound questions while glossing over equally deep issues in our understanding of nature. In this review, I analyze Penrose’s main arguments, emphasizing his presentation of the Second Law conundrum as “the most profound mystery of cosmology”, and discuss his own proposals to (...) overcome the impasse. I especially focus on the capabilities of conformal cyclic cosmology to illuminate the enigma of the extraordinarily low entropy at the Big Bang and review its capacity of success in stipulating a reset for the entropy of the universe. Even though one need not follow Penrose’s tentative answers, which are not immune to serious critiques, much of his view can be shared as a sound starting point in search of “the new physics of the universe.”. (shrink)

It is commonly agreed that the well-known Lucas-Penrose arguments and even Penrose's 'new argument' in [Penrose, R. (1994): Shadows of the Mind, Oxford University Press] are inconclusive. It is, perhaps, less clear exactly why at least the latter is inconclusive. This note continues the discussion in [Lindström, P. (2001): Penrose's new argument, J. Philos. Logic 30, 241-250; Shapiro, S.(2003): Mechanism, truth, and Penrose's new argument, J. Philos. Logic 32, 19-42] and elsewhere of this question.

Il dibattito sul ruolo e le implicazioni del teorema di Gödel per l'intelligenza artificiale ha recentemente ricevuto nuovo impeto grazie a due importanti volumi pubblicati da Roger Penrose, The Emperor's New Mind [1989] e Shadows of the Mind [1994]. Naturalmente, Penrose non è il primo né l'ultimo a usare il teorema di Gödel allo scopo di trarne conseguenze per i fondamenti dell'intelligenza artificiale. Tuttavia il recente dibattito suscitato dai due libri di Penrose è significativo sia per ampiezza sia per (...) profondità. In queste pagine si vuole dare una rassegna di tale dibattito, cominciando dai suoi precursori negli anni '60 (fra cui Lucas, Putnam, e Chihara), per passare poi alle complesse argomentazioni proposte da Penrose e le reazioni di una serie di commentatori (ad esempio Dennett, Feferman, McDermott, Davis). (shrink)

Sections 3.16 and 3.23 of Roger Penrose's Shadows of the mind (Oxford, Oxford University Press, 1994) contain a subtle and intriguing new argument against mechanism, the thesis that the human mind can be accurately modeled by a Turing machine. The argument, based on the incompleteness theorem, is designed to meet standard objections to the original Lucas-Penrose formulations. The new argument, however, seems to invoke an unrestricted truth predicate (and an unrestricted knowability predicate). If so, its premises are inconsistent. The (...) usual ways of restricting the predicates either invalidate Penrose's reasoning or require presuppositions that the mechanist can reject. (shrink)

Using the Godel incompleteness result for leverage, Roger Penrose has argued that the mechanism for consciousness involves quantum gravitational phenomena, acting through microtubules in neurons. We show that this hypothesis is implausible. First the Godel result does not imply that human thought is in fact non-algorithmic. Second, whether or not non-algorithmic quantum gravitational phenomena actually exist, and if they did how that could conceivably implicate microtubules, and if microtubules were involved, how that could conceivably implicate consciousness, is entirely speculative. (...) Third, cytoplasmic ions such as calcium and sodium are almost certainly present in the microtubule pore, barring the quantum-mechanical effects Penrose envisages. Finally, physiological evidence indicates that consciousness does not directly depend on microtubule properties in any case, rendering doubtful any theory according to which consciousness is generated in the microtubules. (shrink)

Roger Penrose is justly famous for his work in physics and mathematics but he is _notorious_ for his endorsement of the Gödel argument (see his 1989, 1994, 1997). This argument, first advanced by J. R. Lucas (in 1961), attempts to show that Gödel’s (first) incompleteness theorem can be seen to reveal that the human mind transcends all algorithmic models of it¹. Penrose's version of the argument has been seen to fall victim to the original objections raised against Lucas (see (...) Boolos (1990) and for a particularly intemperate review, Putnam (1994)). Yet I believe that more can and should be said about the argument. Only a brief review is necessary here although I wish to present the argument in a somewhat peculiar form. (shrink)

Roger Penrose formuló en 1989 un argumento contra la IA. Dicho argumento concluye que la explicación científico-matemática de la realidad es más amplia que la meramente computacional, porque existen ciertos aspectos de la realidad no-computables. Este artículo analiza dicho argumento y la discusión al respecto, para concluir que el tipo de argumento que quiere desarrollar Penrose está viciado de raíz, lo que impide llegar a las conclusiones deseadas. A la vez se sostiene la validez filosófica de sus conclusiones y (...) se apunta a la idea de no-localidad como consistente al hablar sobre la conciencia. (shrink)

In the light of his recent (and fully deserved) Nobel Prize, this pedagogical paper draws attention to a fundamental tension that drove Penrose’s work on general relativity. His 1965 singularity theorem (for which he got the prize) does not in fact imply the existence of black holes (even if its assumptions are met). Similarly, his versatile definition of a singular space–time does not match the generally accepted definition of a black hole (derived from his concept of null infinity). To overcome (...) this, Penrose launched his cosmic censorship conjecture(s), whose evolution we discuss. In particular, we review both his own (mature) formulation and its later, inequivalent reformulation in the pde literature. As a compromise, one might say that in “generic” or “physically reasonable” space–times, weak cosmic censorship postulates the appearance and stability of event horizons, whereas strong cosmic censorship asks for the instability and ensuing disappearance of Cauchy horizons. As an encore, an “Appendix” by Erik Curiel reviews the early history of the definition of a black hole. (shrink)