I argue that at least one of the following propositions is true: the human species is very likely to become extinct before reaching a ’posthuman’ stage; any posthuman civilization is extremely unlikely to run a significant number of simulations of its evolutionary history ; we are almost certainly living in a computer simulation. It follows that the belief that there is a significant chance that we shall one day become posthumans who run ancestor-simulations is false, unless we are currently living (...) in a simulation. I discuss some consequences of this result. (shrink)

The purpose of this paper is to provide an account of the epistemology and metaphysics of universe creation on a computer. The paper begins with F.J.Tipler's argument that our experience is indistinguishable from the experience of someone embedded in a perfect computer simulation of our own universe, hence we cannot know whether or not we are part of such a computer program ourselves. Tipler's argument is treated as a special case of epistemological scepticism, in a similar vein to `brain-in-a-vat' arguments. (...) It is argued that the hypothesis that our universe is a program running on a digital computer in another universe generates empirical predictions, and is therefore a falsifiable hypothesis. The computer program hypothesis is also treated as a hypothesis about what exists beyond the physical world, and is compared with Kant's metaphysics of noumena. It is proposed that a theory about what exists beyond the physical world should be formulated with the precise concepts of mathematics, and should generate physical predictions. It is argued that if our universe is a program running on a digital computer, then our universe must have compact spatial topology, and the possibilities of observationally testing this prediction are considered. The possibility of testing the computer program hypothesis with the value of the density parameter Omega_0 is also analysed. The informational requirements for a computer to represent a universeexactly and completely are considered. Consequent doubt is thrown upon Tipler's claim that if a hierarchy of computer universes exists, we would not be able to know which `level of implementation' our universe exists at. It is then argued that a digital computer simulation of a universe cannot exist as a universe. However, the paper concludes with the acknowledgement that an analog computer simulation can be objectively related to the thing it represents, hence an analog computer simulation of a universe could, in principle, exist as a universe. (shrink)

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.

Zuse proposed that the universe is being computed by some sort of cellular automaton or other discrete computing machinery, challenging the long-held view that some physical laws are continuous by nature. Calculating Space is the title of MIT's English translation of Konrad Zuse's 1969 Rechnender Raum, the first work on digital physics. This is the LaTeX edition by A. German and H. Zenil based on the MIT's English translation with permission from the MIT and Konrad Zuse's son Horst Zuse. Followed (...) by an afterword by A. German and H. Zenil. (shrink)

The Matrix raises several familiar philosophical problems in such new ways that students all over the country are assigning it to their philosophy professors. In so doing, they have offered us a great opportunity to illustrate some of the basic insights of existential phenomenology. The Matrix might seem to renew Descartes’s worry that, since all we ever experience are our own inner mental states, we might, for all we could tell, be living in an illusion created by a malicious demon. (...) In that case, most of our beliefs about reality would be false. But there is a way of understanding The Matrix that denies the mediation of mental states and shows those living in the Matrix to be in direct touch with Matrix reality. The Matrix world is public and objective, not a private subjective dream. Still, there is clearly a sense in which the Matrix world, while not merely mental, is not real either. There is after all a demon—the AI intelligences and their computer—that has in some sense fooled all those who accept the reality of the Matrix world. Thus, the film’s account of our situation is even more disturbing than Descartes’s claim that we are each confined to our own mind. The Matrix world is a vivid illustration of Descartes’s additional prescient claim that we could never be in direct touch with the real world because we are all what we would now call brains in vats. (shrink)

I reply to some recent comments by Brian Weatherson on my 'simulation argument'. I clarify some interpretational matters, and address issues relating to epistemological externalism, the difference from traditional brain-in-a-vat arguments, and a challenge based on 'grue'-like predicates.

MICHAEL WHEELER Cambridge, MA: MIT Press, 2005432 pages, ISBN: 0262232405 (hbk); $35.001.When I was teaching at MIT in the 1960s, students from the Artificial Intelligence Laboratory would come to...

Contestant l’opinion commune selon laquelle le problème de la démarcation, contrairement au problème de l’induction, est relativement anecdotique, l’article soutient que le critère poppérien de falsifiabilité donne une réponse irrésistible à la question de savoir ce qui peut être appris d’une investigation empirique. Tout découle du rejet de la logique inductive, joint à la reconnaissance du fait que, avant d’être investiguée, une hypothèse doit être formulée et acceptée. Les hypothèses scientifiques n’émergent ni a posteriori comme les inductivistes le soutiennent, ni (...) de quelque immaculée source a priori : elles sont des conjectures pures et simples. Les empiristes qui rejettent l’apriorisme ont donc rejoint trop rapidement les rangs non philosophiques du naturalisme épistémologique. L’article conclut par un résumé de l’objectivisme popperien et par de brèves réponses à certains arguments à la mode selon lesquels la vérité objective n’est pas un objectif atteignable. (shrink)

This paper concerns Alan Turing’s ideas about machines, mathematical methods of proof, and intelligence. By the late 1930s, Kurt Gödel and other logicians, including Turing himself, had shown that no finite set of rules could be used to generate all true mathematical statements. Yet according to Turing, there was no upper bound to the number of mathematical truths provable by intelligent human beings, for they could invent new rules and methods of proof. So, the output of a human mathematician, for (...) Turing, was not a computable sequence (i.e., one that could be generated by a Turing machine). Since computers only contained a finite number of instructions (or programs), one might argue, they could not reproduce human intelligence. Turing called this the “mathematical
objection” to his view that machines can think. Logico-mathematical reasons, stemming from his own work, helped to convince Turing that it should be possible to reproduce human intelligence, and eventually compete with it, by developing the appropriate kind of digital computer. He felt it
should be possible to program a computer so that it could learn or discover new rules, overcoming the limitations imposed by the incompleteness and undecidability results in the same way that human
mathematicians presumably do. (shrink)

In his bestselling work of popular science, Sir Roger Penrose takes us on a fascinating roller-coaster ride through the basic principles of physics, cosmology, mathematics, and philosophy to show that human thinking can never be emulated by a machine.

The purpose of this paper is to provide an account of the epistemology and metaphysics of universe creation on a computer. The paper begins with F.J.Tipler's argument that our experience is indistinguishable from the experience of someone embedded in a perfect computer simulation of our own universe, hence we cannot know whether or not we are part of such a computer program ourselves. Tipler's argument is treated as a special case of epistemological scepticism, in a similar vein to `brain-in-a-vat' arguments. (...) It is argued that the hypothesis that our universe is a program running on a digital computer in another universe generates empirical predictions, and is therefore a falsifiable hypothesis. The computer program hypothesis is also treated as a hypothesis about what exists beyond the physical world, and is compared with Kant's metaphysics of noumena. It is proposed that a theory about what exists beyond the physical world should be formulated with the precise concepts of mathematics, and should generate physical predictions. It is argued that if our universe is a program running on a digital computer, then our universe must have compact spatial topology, and the possibilities of observationally testing this prediction are considered. The possibility of testing the computer program hypothesis with the value of the density parameter Omega_0 is also analysed. The informational requirements for a computer to represent a universeexactly and completely are considered. Consequent doubt is thrown upon Tipler's claim that if a hierarchy of computer universes exists, we would not be able to know which `level of implementation' our universe exists at. It is then argued that a digital computer simulation of a universe cannot exist as a universe. However, the paper concludes with the acknowledgement that an analog computer simulation can be objectively related to the thing it represents, hence an analog computer simulation of a universe could, in principle, exist as a universe. (shrink)