Nick Bostrom’s ‘Simulation Argument’ purports to show that, unless we are confident that advanced ‘posthuman’ civilizations are either extremely rare or extremely rarely interested in running simulations of their own ancestors, we should assign significant credence to the hypothesis that we are simulated. I argue that Bostrom does not succeed in grounding this constraint on credence. I first show that the Simulation Argument requires a curious form of selective scepticism, for it presupposes that we possess good (...) evidence for claims about the physical limits of computation and yet lack good evidence for claims about our own physical constitution. I then show that two ways of modifying the argument so as to remove the need for this presupposition fail to preserve the original conclusion. Finally, I argue that, while there are unusual circumstances in which Bostrom’s selective scepticism might be reasonable, we do not currently find ourselves in such circumstances. There is no good reason to uphold the selective scepticism the Simulation Argument presupposes. There is thus no good reason to believe its conclusion. (shrink)

This article reports on a newly discovered bug in the original simulation argument. Two different ways of patching the argument are proposed, each of which preserves the original conclusion.

Anthony Brueckner, in a recent article, proffers ‘a new way of thinking about Bostrom's Simulation Argument’ . His comments, however, misconstrue the argument; and some words of explanation are in order.The Simulation Argument purports to show, given some plausible assumptions, that at least one of three propositions is true . Roughly stated, these propositions are: almost all civilizations at our current level of development go extinct before reaching technological maturity; there is a strong convergence among (...) technologically mature civilizations such that almost all of them lose interest in creating ancestor-simulations; almost all people with our sorts of experiences live in computer simulations. I also argue that conditional on you should assign a very high credence to the proposition that you live in a computer simulation. However, pace Brueckner, I do not argue that we should believe that we are in simulation. 1 In fact, I believe that we are probably not simulated. The Simulation Argument purports to show only that, as well as , at least one of – is true; but it does not tell us which one.Brueckner also writes: " It is worth noting that one reason why Bostrom thinks that the number of Sims [computer-generated minds with experiences similar to those typical of normal, embodied humans living in a Sim-free early 21 st century world] will vastly outstrip the number of humans is that Sims ‘will run their … ". (shrink)

Some philosophers regard it as a serious possibility that we now exist within a simulation. That this hypothesis is somewhat probable has been defended extensively by Nick Bostrom. Notably, Bostrom does not defend the conclusion that we inhabit a simulation, but rather the disjunctive conclusion that the human species is very likely to die out before reaching a ‘posthuman stage’, that posthuman civilizations are extremely unlikely to run significant numbers of simulations, or that we almost certainly inhabit a (...) simulation. Bostrom argues that there is no basis for strongly favouring one of these alternatives over its counterparts. The upshot is that it is fairly probable that we inhabit a simulation. I argue that posthuman civilizations are likely to be unwilling to run significant numbers of simulations, thereby undermining the case for assigning a somewhat high probability to the hypothesis that we live in a simulation. (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.

Inspired by anthropic reasoning behind Doomsday arguments, Nick Bostrom's Simulation Argument says: people who think advanced civilisations would run many fully-conscious simulated minds should also think they're probably simulated minds themselves. However, Bostrom's conclusions can be resisted, especially by sympathisers with Doomsday or anthropic reasoning. This paper initially offers a posterior-probabilistic ‘Doomsday lottery’ argument against Bostrom's conclusions. Suggestions are then offered for deriving anti-simulation conclusions using weaker assumptions. Anti-simulation arguments herein use more robust reference classes (...) than Bostrom's argument, require no Principles of Indifference, abide better by the total evidence requirement, and yet use empirically plausible priors and likelihoods. However, while Doomsday arguments are probabilistically, epistemically and metaphysically stronger than the Simulation Argument, anthropic reasoning can refrain from embracing either. (shrink)

Various theorists contend that we may live in a computer simulation. David Chalmers in turn argues that the simulation hypothesis is a metaphysical hypothesis about the nature of our reality, rather than a sceptical scenario. We use recent work on consciousness to motivate new doubts about both sets of arguments. First, we argue that if either panpsychism or panqualityism is true, then the only way to live in a simulation may be as brains-in-vats, in which case it (...) is unlikely that we live in a simulation. We then argue that if panpsychism or panqualityism is true, then viable simulation hypotheses are substantially sceptical scenarios. We conclude that the nature of consciousness has wide-ranging implications for simulation arguments. (shrink)

Nick Bostrom’s Simulation Argument (SA) has many intriguing theological implications. We work out some of them here. We show how the SA can be used to develop novel versions of the Cosmological and Design Arguments. We then develop some of the affinities between Bostrom's naturalistic theogony and more traditional theological topics. We look at the resurrection of the body and at theodicy. We conclude with some reflections on the relations between the SA and Neoplatonism (friendly) and between the (...) SA and theism (less friendly). (shrink)

The Doomsday Argument and the Simulation Argument share certain structural features, and hence are often discussed together. Both are cases where reflecting on one’s location among a set of possibilities yields a counter-intuitive conclusion—in the first case that the end of humankind is closer than you initially thought, and in the second case that it is more likely than you initially thought that you are living in a computer simulation. Indeed, the two arguments do have some (...) structural similarities. But there are also significant disanalogies between the two arguments, and I argue that these disanalogies mean that the Simulation Argument succeeds and the Doomsday Argument fails. (shrink)

Nick Bostrom’s “simulation argument” purports to show that if it is possible to create and run a vast number of computer simulations indistinguishable from the reality we are living in, then it is highly probable that we are already living in a computer simulation. However, the simulation argument requires a modification to escape the undermining implications of the scepticism it implies, as argued by Birch. The present paper shows that, even if the modified simulation (...) argument is valid, still it is unsound since it relies on the indistinguishability assumption that even in principle cannot be tested. To account for the unsoundness of the simulation argument, the present paper draws on John Woods' theory of fiction, to expose structural similarities between general fiction and the simulation argument. Though the simulation argument is unsound, it seems persuasive, because the argument immerses the reader in a fictive world with the help of tacit assumptions, leveraging just enough common sense to remain compelling while covering over an untestable premise. Simultaneously with the critique of Bostrom’s argument, Chalmers' argument for the matrix hypothesis is assessed on similar criteria. In either case, both arguments rely on an accumulation of assumptions, both implicit and explicit, hiding the premises that are untestable in principle. (shrink)

The simulation hypothesis claims that the whole observable universe, including us, is a computer simulation implemented by technologically advanced beings for an unknown purpose. The simulation argument (as I reconstruct it) is an argument for this hypothesis with moderately plausible premises. I develop two lines of objection to the simulation argument. The first takes the form of a structurally similar argument for a conflicting conclusion, the claim that I am a so-called freak (...) observer, formed spontaneously in a quantum or thermodynamic fluctuation rather than through ordinary processes of evolution and growth. The second rejects the basic line of reasoning of both arguments: the sort of evidence they cite is not capable of supporting either the claim that I am a simulant or the claim that I am a freak observer. The evidence that simulants or freak observers exist is not a reason to think that I am one of them. (shrink)

According to the most common interpretation of the simulation argument, we are very likely to live in an ancestor simulation. It is interesting to ask if some families of simulations are more likely than others inside the space of all simulations. We argue that a natural probability measure is given by computational complexity: easier simulations are more likely to be run. Remarkably this allows us to extract experimental predictions from the fact that we live in a (...) class='Hi'>simulation. For instance we show that it is very likely that humanity will not achieve interstellar travel and that humanity will not meet other intelligent species in the universe, in turn explaining the Fermi's Paradox. On the opposite side, experimental falsification of any of these predictions would constitute evidence against our reality being a simulation. (shrink)

Both patched versions of the Bostrom/Kulczycki simulation argument contain serious objective errors, discovered while attempting to formalize them in predicate logic. The English glosses of both versions involve badly misleading meanings of vague magnitude terms, which their impressiveness benefits from. We fix the errors, prove optimal versions of the arguments, and argue that both are much less impressive than they originally appeared. Finally, we provide a guide for readers to evaluate the simulation argument for themselves, using (...) well-justified settings of the argument parameters that have simple, accurate statements in English, which are easier to understand and critique than the statements in the original paper. (shrink)

N. Bostrom’s simulation argument and two additional assumptions imply that we likely live in a computer simulation. The argument is based upon the following assumption about the workings of realistic brain simulations: The hardware of a computer on which a brain simulation is run bears a close analogy to the brain itself. To inquire whether this is so, I analyze how computer simulations trace processes in their targets. I describe simulations as fictional, mathematical, pictorial, and (...) material models. Even though the computer hardware does provide a material model of the target, this does not suffice to underwrite the simulation argument because the ways in which parts of the computer hardware interact during simulations do not resemble the ways in which neurons interact in the brain. Further, there are computer simulations of all kinds of systems, and it would be unreasonable to infer that some computers display consciousness just because they simulate brains rather than, say, galaxies. (shrink)

The point of this note is to compare the Doomsday Argument to the Simulation Argument. The latter, I maintain, is a better argument than the former.

I propose in this paper a solution to the problem arising from the Simulation argument. I describe first Bostrom's Simulation Argument in detail and its inherent problem. I recall then the implicit analogy underlying the Simulation argument. I show then the inadequacy of this analogy, by pointing out a disanalogy between the human situation corresponding to the Simulation Argument and its underlying urn analogy. I point out that such disanalogy is also present (...) within the Emerald case, another thought experiment imagined by John Leslie. I proceed then to build an alternative analogy, which fits more adequately with the human situation corresponding to the Simulation Argument. I draw lastly the consequences of the presence of two alternative analogies on the conclusion of the Simulation Argument. (shrink)

Paul Franceschi | : Je présente dans cet article une analyse de l’argument de la Simulation selon le point de vue du contextualisme dialectique, fondée sur le problème de la classe de référence. Je décris tout d’abord l’argument de la Simulation de manière détaillée. J’identifie ensuite la classe de référence et j’applique successivement l’argument à trois classes de référence distinctes : les simulations conscientes de leur propre nature de simulation, les simulations imparfaites et les (...) simulations à immersion. Finalement, je montre qu’il existe trois niveaux de conclusion dans l’argument de la Simulation, selon la classe de référence choisie, qui engendrent des conclusions finales d’une nature très différente. | : I present in this paper an analysis of the Simulation argument from a dialectical contextualist standpoint. This analysis is grounded on the reference class problem. I begin with describing in detail Bostrom’s Simulation Argument. I identify then the reference class within the Simulation argument. I also point out a reference class problem, by applying the argument successively to three different reference classes : aware-simulations, imperfect simulations and immersion-simulations. Finally, I point out that there are three levels of conclusion within the Simulation Argument, depending on the chosen reference class, that yield each final conclusions of a fundamentally different nature. (shrink)

We examine how opinion on a controversial real-world issue shifts as a function of reading relevant arguments and engaging in a specific mental simulation about a future, fictional state of affairs involving the target issue. Individuals thought either counterfactually about a future event (“if only X had not happened …”) or semifactually about it (“even if X had not happened …”). In Experiment 1, as expected, individuals became more in favour of a course of action (the electronic tagging of (...) children) after reading relevant supporting arguments. They also became more in favour after they thought counterfactually how a negative future event could have been avoided if only electronic tagging had not been banned some years earlier. The effects of argument relevance and type of mental simulation were additive. Using a similar procedure but a different target issue (whether the UK should join the Economic Monetary Union), Experiment 2 confirmed that the type of mental simulation exerts a substantial effect on the impact of relevant arguments. Much weaker effects arose when the mental simulation was not relevant to the target issue. We set and discuss our results in terms of dual-processing theory. (shrink)

According to the Argument from Disagreement (AD) widespread and persistent disagreement on ethical issues indicates that our moral opinions are not influenced by moral facts, either because there are no such facts or because there are such facts but they fail to influence our moral opinions. In an innovative paper, Gustafsson and Peterson (Synthese, published online 16 October, 2010) study the argument by means of computer simulation of opinion dynamics, relying on the well-known model of Hegselmann and (...) Krause (J Artif Soc Soc Simul 5(3):1–33, 2002; J Artif Soc Soc Simul 9(3):1–28, 2006). Their simulations indicate that if our moral opinions were influenced at least slightly by moral facts, we would quickly have reached consensus, even if our moral opinions were also affected by additional factors such as false authorities, external political shifts and random processes. Gustafsson and Peterson conclude that since no such consensus has been reached in real life, the simulation gives us increased reason to take seriously the AD. Our main claim in this paper is that these results are not as robust as Gustafsson and Peterson seem to think they are. If we run similar simulations in the alternative Laputa simulation environment developed by Angere and Olsson (Angere, Synthese, forthcoming and Olsson, Episteme 8(2):127–143, 2011) considerably less support for the AD is forthcoming. (shrink)

I have developed transcendental arguments to refute several versions of Nick Bostrom’s simulation hypothesis. I called some of these arguments the SIM-style argument. In this paper, I have four main aims. First, I employ the SIM-style argument to remedy a defect in Hilary Putnam’s Brain-in-vat argument. Second, I show that the most radical skepticism, which Tim Button called the nightmarish Cartesian skepticism, can be refuted by the SIM-style argument or by another transcendental argument I (...) develop here. Third, I compare my approach to radical skepticisms with Donald Davidson’s, as it is often regarded as an exemplar of transcendental arguments. Fourth, I explain how the prominent objections, mainly developed by Barry Stroud, to transcendental arguments can incur two undesirable results: psychologism and Kantian skepticism. (shrink)

I introduce the implantation argument, a new argument for the existence of God. Spatiotemporal extensions believed to exist outside of the mind, composing an external physical reality, cannot be composed of either atomlessness, or of Democritean atoms, and therefore the inner experience of an external reality containing spatiotemporal extensions believed to exist outside of the mind does not represent the external reality, the mind is a mere cinematic-like mindscreen, implanted into the mind by a creator-God. It will be (...) shown that only a creator-God can be the implanting creator of the mindscreen simulation, and other simulation theories, such as Bostrom’s famous account, that do not involve a creator-God as the mindscreen simulation creator, involve a reification fallacy. (shrink)

Theory theorists conceive of social cognition as a theoretical and observational enterprise rather than a practical and interactive one. According to them, we do our best to explain other people's actions and mental experience by appealing to folk psychology as a kind of rule book that serves to guide our observations through our puzzling encounters with others. Seemingly, for them, most of our encounters count as puzzling, and other people are always in need of explanation. By contrast, simulation theorists (...) do their best to avoid the theoretical stance by using their own experience as the measure of everyone else's. When it comes to explaining how we understand other people some of the very best contemporary philosophers, psychologists, and neuroscientists are simulationists. For example, Vittorio Gallese, Alvin Goldman, Robert Gordon, Jane Heal, Susan Hurley, and Marc Jeannerod. This short list of simulationists, however, already involves some problems. Not everyone on this list understands simulation in the same way. In effect, there are different simulation theories, and although it is important to distinguish them, and I will do so before I go much further, I will in the end argue against all of them. For several reasons I don't think that the concept of simulation explains our primary and pervasive way of understanding others, any more than theory theory does. (shrink)

In this paper, I propose that, in addition to the multiverse hypothesis, which is commonly taken to be an alternative explanation for fine-tuning, other than the design hypothesis, the simulation hypothesis is another explanation for fine-tuning. I then argue that the simulation hypothesis undercuts the alleged evidential connection between ‘designer’ and ‘supernatural designer of immense power and knowledge’ in much the same way that the multiverse hypothesis undercuts the alleged evidential connection between ‘fine-tuning’ and ‘fine-tuner’ (or ‘designer’). If (...) this is correct, then the fine-tuning argument is a weak argument for the existence of God. (shrink)

We defend the Simulation Theory of Mind against a challenge from the Theory Theory of Mind. The challenge is that while Simulation Theory can account for Theory of Mind errors, it cannot account for their systematic nature. There are Theory of Mind errors seen in social psychological research with adults where persons are either overly generous or overly cynical in how rational they expect others to be. There are also Theory of Mind errors observable in developmental data drawn (...) from Maxi-type false belief tests. We provide novel responses to several examples showing that Simulation Theory can answer these challenges. (shrink)

Preston Greene (2020) argues that we should not conduct simulation investigations because of the risk that we might be terminated if our world is a simulation designed to research various counterfactuals about the world of the simulators. In response, we propose a sequence of arguments, most of which have the form of an "even if” response to anyone unmoved by our previous arguments. It runs thus: (i) if simulation is possible, then simulators are as likely to care (...) about simulating simulations as they are likely to care about simulating basement (i.e. non-simulated) worlds. But (ii) even if simulations are interested only in simulating basement worlds the discovery that we are in a simulation will have little or no impact on the evolution of ordinary events. But (iii) even if discovering that we are in a simulation impacts the evolution of ordinary events, the effects of seeming to do so could also happen in a basement world, and might be the subject of interesting counterfactuals in the basement world Finally, (iv) there is little reason to think that there is a catastrophic effect from successful simulation probes, and no argument from the precautionary principle can be used to leverage the negligible credence one ought have in this. Thus, if we do develop a simulation probe, then let’s do it. (shrink)

Nick Bostrom’s recently patched ‘‘simulation argument’’ (Bostrom in Philos Q 53:243–255, 2003; Bos- trom and Kulczycki in Analysis 71:54–61, 2011) purports to demonstrate the probability that we ‘‘live’’ now in an ‘‘ancestor simulation’’—that is as a simulation of a period prior to that in which a civilization more advanced than our own—‘‘post-human’’—becomes able to simulate such a state of affairs as ours. As such simulations under consid- eration resemble ‘‘brains in vats’’ (BIVs) and may appear open (...) to similar objections, the paper begins by reviewing objections to BIV-type proposals, specifically those due a presumed mad envatter. In counter example, we explore the motivating rationale behind current work in the development of psychologically realistic social simula- tions. Further concerns about rendering human cognition in a computational medium are confronted through review of current dynamic systems models of cognitive agency. In these models, aspects of the human condition are repro- duced that may in other forms be considered incomputable, i.e., political voice, predictive planning, and consciousness. The paper then argues that simulations afford a unique potential to secure a post-human future, and may be nec- essary for a pre-post-human civilization like our own to achieve and to maintain a post-human situation. Long-s- tanding philosophical interest in tools of this nature for Aristotle’s ‘‘statesman’’ and more recently for E.O. Wilson in the 1990s is observed. Self-extinction-level threats from State and individual levels of organization are compared, and a likely dependence on large-scale psychologically realistic simulations to get past self-extinction-level threats is projected. In the end, Bostrom’s basic argument for the conviction that we exist now in a simulation is reaffirmed. (shrink)

In this paper we shed new light on the Argument from Disagreement by putting it to test in a computer simulation. According to this argument widespread and persistent disagreement on ethical issues indicates that our moral opinions are not influenced by any moral facts, either because no such facts exist or because they are epistemically inaccessible or inefficacious for some other reason. Our simulation shows that if our moral opinions were influenced at least a little bit (...) by moral facts, we would quickly have reached consensus, even if our moral opinions were affected by factors such as false authorities, external political shifts, and random processes. Therefore, since no such consensus has been reached, the simulation gives us increased reason to take seriously the Argument from Disagreement. Our conclusion is however not conclusive; the simulation also indicates what assumptions one has to make in order to reject the Argument from Disagreement. The simulation algorithm we use builds on the work of Hegselmann and Krause (J Artif Soc Social Simul 5(3); 2002, J Artif Soc Social Simul 9(3), 2006). (shrink)

From obnoxious public figures to online trolling and accusations of “fake news”, almost no one seems able to disagree without hostility. But polite discord sounds farfetched when issues are so personal and fundamental that those on opposing sides appear to have no common ground. How do you debate the “enemy”? Philosophers Scott Aikin and Robert Talisse show that disagreeing civilly, even with your sworn enemies, is a crucial part of democracy. Rejecting the popular view that civility requires a polite and (...) concessive attitude, they argue that our biggest challenge is not remaining calm in the face of an opponent, but rather ensuring that our political arguments actually address those on the opposing side. Too often politicians and pundits merely simulate political debate, offering carefully structured caricatures of their opponents. These simulations mimic political argument in a way designed to convince citizens that those with whom they disagree are not worth talking to. Good democracy thrives off conflict, but until we learn the difference between real and simulated arguments we will be doomed to speak at cross-purposes. Aikin and Talisse provide a crash course in political rhetoric for the concerned citizen, showing readers why understanding the structure of arguments is just as vital for a healthy democracy as debate over facts and values. But there’s a sting in the tail - no sooner have we learned rhetorical techniques for better disagreement than these techniques themselves become weapons with which to ignore our enemies, as accusations like “false equivalence” and “ad hominem” are used to silence criticism. Civility requires us to be eternally vigilant to the ways we disagree. (shrink)

This paper develops a natural-language agent-based model of argumentation (ABMA). Its artificial deliberative agents (ADAs) are constructed with the help of so-called neural language models recently developed in AI and computational linguistics. ADAs are equipped with a minimalist belief system and may generate and submit novel contributions to a conversation. The natural-language ABMA allows us to simulate collective deliberation in English, i.e. with arguments, reasons, and claims themselves — rather than with their mathematical representations (as in symbolic models). This paper (...) uses the natural-language ABMA to test the robustness of symbolic reason-balancing models of argumentation (Mäs & Flache 2013; Singer et al. 2019): First of all, as long as ADAs remain passive, confirmation bias and homophily updating trigger polarization, which is consistent with results from symbolic models. However, once ADAs start to actively generate new contributions, the evolution of a conversation is dominated by properties of the agents as authors. This suggests that the creation of new arguments, reasons, and claims critically affects a conversation and is of pivotal importance for understanding the dynamics of collective deliberation. The paper closes by pointing out further fruitful applications of the model and challenges for future research. (shrink)

In this paper I critically evaluate the Devil Simulation Argument for cognitive immoralism—the position that moral flaws with a work of art can be cognitively virtuous, and thereby artistically valuable. I focus on Matthew Kieran's version of the argument. Kieran holds that by simulating the attitudes of fictional devils we can come to gain important moral insights. In response, I argue that we have no reason to believe that we can effectively adopt immoral attitudes, that any successful (...) narrative artworks ask us to do so, or that it would be an effective means of moral instructions. (shrink)

Historically, the hypothesis that our world is a computer simulation has struck many as just another improbable-but-possible “skeptical hypothesis” about the nature of reality. Recently, however, the simulation hypothesis has received significant attention from philosophers, physicists, and the popular press. This is due to the discovery of an epistemic dependency: If we believe that our civilization will one day run many simulations concerning its ancestry, then we should believe that we are probably in an ancestor simulation right (...) now. This essay examines a troubling but underexplored feature of the ancestor-simulation hypothesis: the termination risk posed by both ancestor-simulation technology and experimental probes into whether our world is an ancestor simulation. This essay evaluates the termination risk by using extrapolations from current computing practices and simulation technology. The conclusions, while provisional, have great implications for debates concerning the fundamental nature of reality and the safety of contemporary physics. (shrink)

It's uncontroversial that notions of idealization and approximation are central to understanding computer simulations and their rationale. What's not so clear is what exactly these notions come to. Two distinct forms of approximation will be distinguished and their features contrasted with those of idealizations. These distinctions will be refined and closely tied to computer simulations by means of Scott-Strachey denotational programming semantics. The use of this sort of semantics also provides a convenient format for argumentation in favor of several theses (...) I shall propose concerning the role computer implemented approximations and idealizations play in fixing what the acceptance of an underlying scientific theory is or should be. (shrink)

Computer simulations and experiments share many important features. One way of explaining the similarities is to say that computer simulations just are experiments. This claim is quite popular in the literature. The aim of this paper is to argue against the claim and to develop an alternative explanation of why computer simulations resemble experiments. To this purpose, experiment is characterized in terms of an intervention on a system and of the observation of the reaction. Thus, if computer simulations are experiments, (...) either the computer hardware or the target system must be intervened on and observed. I argue against the first option using the non-observation argument, among others. The second option is excluded by e.g. the over-control argument, which stresses epistemological differences between experiments and simulations. To account for the similarities between experiments and computer simulations, I propose to say that computer simulations can model possible experiments and do in fact often do so. (shrink)

We review the major phenomena of skilled typing and propose a model for the control of the hands and fingers during typing. The model is based upon an Activation‐Trigger‐Schema system in which a hierarchical structure of schemata directs the selection of the letters to be typed and, then, controls the hand and finger movements by a cooperative, relaxation algorithm. The interactions of the patterns of activation and inhibition among the schemata determine the temporal ordering for launching the keystrokes. To account (...) for the phenomena of doubling errors, the model has only “type” schemata—no “token” schemata—with only a weak binding between the special schema that signals a doubling, and its argument. The model exists as a working computer simulation and produces an output display of the hands and fingers moving over the keyboard. It reproduces some of the major phenomena of typing, including the interkeystroke interval times, the pattern of transposition errors found in skilled typists, and doubling errors. Although the model is clearly inadequate or wrong in some of its features and assumptions, it serves as a useful first approximation for the understanding of skilled typing. (shrink)

Recent philosophical discussions of our capacity to attribute mental states to other human beings, and to produce accurate predictions and informative explanations of their behavior which make reference to the content of those states have focused on two apparently contrasting ways in which we might hope to account for these abilities. The first is that of regarding our competence as being under-girded by our grasp of a tacit psychological theory. The second builds on the idea that in trying to get (...) a grip on the mental lives of others we might be able to draw on the fact that we are ourselves subjects of mental states in order to simulate their mental processes. Call these the theory view and the simulation view. In this paper I wish to discuss an argument—which I shall call Collapse—to the effect that if our capacities can be explained in the way that the simulationist supposes then they can also be explained along lines that the advocate of the theory view favours. I am not the first person with simulationist sympathies to have addressed this argument. However, my response is somewhat less concessive than others in the literature: while they attempt to soften its force by attempting to reformulate the simulationist view in a way that evades the conclusion of the argument, I attempt to meet it head on and to show that it does not even succeed in refuting the version of simulationism which it takes as its target. (shrink)

According to a popular strategy amongst economists and philosophers, in order to solve the problem of interpersonal utility comparisons, we have to look at how ordinary people make such comparisons in everyday life. The most recent attempt to develop this strategy has been put forward by Goldman in his “Simulation and Interpersonal Utility” (Ethics 4:709–726, 1995). Goldman claims, first, that ordinary people make interpersonal comparisons by simulation and, second, that simulation is reliable for making interpersonal comparisons. In (...) this paper, I focus on Goldman’s latter claim. After updating Goldman’s account of how ordinary people make interpersonal comparisons in the light of Goldman’s newest formulation of his simulation theory of mental ascription (Goldman, Simulating Minds. Oxford University Press, Oxford, 2006), I develop and assess Goldman’s arguments in favour of the reliability of simulation for interpersonal comparisons. I argue that, under certain conditions, there may be room for a scientifically acceptable solution to the problem of interpersonal utility comparisons. (shrink)

What is the simulation theory? Arguments for simulation theory Simulation theory versus theory theory Simulation theory and cognitive science Versions of simulation theory A possible test of the simulation theory.

It is often claimed that scientists can obtain new knowledge about nature by running computer simulations. How is this possible? I answer this question by arguing that computer simulations are arguments. This view parallels Norton’s argument view about thought experiments. I show that computer simulations can be reconstructed as arguments that fully capture the epistemic power of the simulations. Assuming the extended mind hypothesis, I furthermore argue that running the computer simulation is to execute the reconstructing argument. (...) I discuss some objections and reject the view that computer simulations produce knowledge because they are experiments. I conclude by comparing thought experiments and computer simulations, assuming that both are arguments. (shrink)

I present arguments against both explicit and implicit versions of the simulation theory for intersubjective understanding. Logical, developmental, and phenomenological evidence counts against the concept of explicit simulation if this is to be understood as the pervasive or default way that we understand others. The concept of implicit (subpersonal) simulation, identified with neural resonance systems (mirror systems or shared representations), fails to be the kind of simulation required by simulation theory, because it fails to explain (...) how neuronal processes meet constraints that involve instrumentality and pretense. Implicit simulation theory also fails to explain how I can attribute a mental or emotion state that is different from my own to another person. I also provide a brief indication of an alternative interpretation of neural resonance systems. (shrink)

It is sometimes said that simulation can serve as epistemic substitute for experimentation. Such a claim might be suggested by the fast-spreading use of computer simulation to investigate phenomena not accessible to experimentation. But what does that mean? The paper starts with a clarification of the terms of the issue and then focuses on two powerful arguments for the view that simulation and experimentation are ‘epistemically on a par’. One is based on the claim that, in experimentation, (...) no less than in simulation, it is not the system under study that is manipulated but a system that ‘stands-in’ for it. The other one highlights the pervasive use of models in experimentation. It will be argued that these arguments, as compelling as they might seem, are each based on a mistaken interpretation of experimentation and that, far from simulation and experimentation being epistemically on a par, they do not have the same epistemic function, do not produce the same kind of epistemic results. (shrink)

Church's thesis, that all reasonable definitions of “computability” are equivalent, is not usually thought of in terms of computability by acontinuouscomputer, of which the general-purpose analog computer (GPAC) is a prototype. Here we prove, under a hypothesis of determinism, that the analytic outputs of aC∞GPAC are computable by a digital computer.In [POE, Theorems 5, 6, 7, and 8], Pour-El obtained some related results. (The proof there of Theorem 7 depends on her Theorem 2, for which the proof in [POE] is (...) incorrect, but for which a correct proof is given in [LIR]. Also, the proof in [POE] of Theorem 8 depends on the unproved assertion that a solution of an algebraic differential equation must be analytic on an open subset of its domain. However, this assertion was later proved in [BRR].) As in [POE], we reduce the problem to a problem about solutions of certain systems of algebraic differential equations (ADE's). If such a system is nonsingular (i.e. if the “separant” does not vanish along the given solution), then the argument is very easy (see [VSD] for an even simpler situation), so that the essential difficulties arise fromsingularsystems. Our main tools in handling these difficulties are drawn from the excellent (and difficult) paper [DEL] by Denef and Lipshitz. The author especially wants to thank Leonard Lipshitz for his kind help in the preparation of the present paper.We emphasize here that our proof of the simulation result applies only to the GPAC as described below. The GPAC's form a natural subclass of the class of all analog computers, and are based on certain idealized components (“black boxes”), mostly associated with the technology of past decades. One can easily envisage other kinds of black boxes of an input-output character that would lead to different kinds of analog computers. (For example, one could incorporate delays, or spatial integrators in addition to the present temporal integrators, etc.) Whether digital simulation is possible for these “extended” analog computers poses a rich and challenging set of research questions. (shrink)

I present a new argument that we are much more likely to be living in a computer simulation than in the ground-level of reality. (Similar arguments can be marshalled for the view that we are more likely to be Boltzmann brains than ordinary people, but I focus on the case of simulations.) I explain how this argument overcomes some objections to Bostrom’s classic argument for the same conclusion. I also consider to what extent the argument (...) depends upon an internalist conception of evidence, and I refute the common line of thought that finding many simulations being run—or running them ourselves—must increase the odds that we are in a simulation. (shrink)