What does it mean to trust the results of a computer simulation? This paper argues that trust in simulations should be grounded in empirical evidence, good engineering practice, and established theoretical principles. Without these constraints, computer simulation risks becoming little more than speculation. We argue against two prominent positions in the epistemology of computer simulation and defend a conservative view that emphasizes the difference between the norms governing scientific investigation and those governing ordinary epistemic practices.

Transmission of justification across inference is a valuable and indeed ubiquitous epistemic phenomenon in everyday life and science. It is thanks to the phenomenon of epistemic transmission that inferential reasoning is a means for substantiating predictions of future events and, more generally, for expanding the sphere of our justified beliefs or reinforcing the justification of beliefs that we already entertain. However, transmission of justification is not without exceptions. As a few epistemologists have come to realise, more or less trivial forms (...) of circularity can prevent justification from transmitting from p to q even if one has justification for p and one is aware of the inferential link from p to q. In interesting cases this happens because one can acquire justification for p only if one has independent justification for q. In this case the justification for q cannot depend on the justification for p and the inferential link from p to q, as genuine transmission would require. The phenomenon of transmission failure seems to shed light on philosophical puzzles, such as Moore's proof of a material world and McKinsey's paradox, and it plays a central role in various philosophical debates. For this reason it is being granted continued and increasing attention. (shrink)

Computer simulations have conventionally been understood to be either extensions of formal methods such as mathematical models or as special cases of empirical practices such as experiments. Here, I argue that computer simulations are best understood as instruments. Understanding them as such can better elucidate their actual role as well as their potential epistemic standing in relation to science and other scientific methods, practices and devices.

It is well known that the probabilistic relation of confirmation is not transitive in that even if E confirms H1 and H1 confirms H2, E may not confirm H2. In this paper we distinguish four senses of confirmation and examine additional conditions under which confirmation in different senses becomes transitive. We conduct this examination both in the general case where H1 confirms H2 and in the special case where H1 also logically entails H2. Based on these analyses, we argue that (...) the Screening-Off Condition is the most important condition for transitivity in confirmation because of its generality and ease of application. We illustrate our point with the example of Moore’s “proof” of the existence of a material world, where H1 logically entails H2, the Screening-Off Condition holds, and confirmation in all four senses turns out to be transitive. (shrink)

Crispin Wright has given an explanation of how a first time warrant can fall short of transmitting across a known entailment. Formal epistemologists have struggled to turn Wright’s informal explanation into cogent Bayesian reasoning. In this paper, I analyse two Bayesian models of Wright’s account respectively proposed by Samir Okasha and Jake Chandler. I argue that both formalizations are unsatisfactory for different reasons, and I lay down a third Bayesian model that appears to me to capture the valid kernel of (...) Wright’s explanation. After this, I consider a recent development in Wright’s account of transmission failure. Wright suggests that his condition sufficient for transmission failure of first time warrant also suffices for transmission failure of supplementary warrant. I propose an interpretation of Wright’s suggestion that shield it from objections. I then lay down a fourth Bayesian framework that provides a simplified model of the unified explanation of transmission failure envisaged by Wright. (shrink)

Duncan Pritchard recently proposed a Wittgensteinian solution to closure-based skepticism. According to Wittgenstein, all epistemic systems assume certain truths. The notions that we are not disembodied brains, that the Earth has existed for a long time and that one’s name is such-and-such all function as “hinge commitments.” Pritchard views a hinge commitment as a positive propositional attitude that is not a belief. Because closure principles concern only knowledge-apt beliefs, they do not apply to hinge commitments. Thus, from the fact that (...) a subject knows that he is sitting in a room, and the fact that the subject’s sitting in a room entails his bodily existence, it does not follow that the subject also knows that he is not an envatted brain. This paper rejects Pritchard’s non-belief reading of hinge commitments. I start by showing that the non-belief reading fails to solve the skeptical paradox because the reasons that Pritchard uses to support the non-belief reading do not exempt hinge propositions from closure principles. I then proceed to argue that the non-belief reading is false as it claims that hinge commitments, unlike ordinary beliefs, are rationally unresponsive—with the help of a scenario in which a subject’s experience is internally chaotic, we can safely conclude that the hinge commitment that one is not systematically mistaken about the world is equally responsive to one’s evidential situations. (shrink)

It is well known that the probabilistic relation of confirmation is not transitive in that even if E confirms H1 and H1 confirms H2, E may not confirm H2. In this paper we distinguish four senses of confirmation and examine additional conditions under which confirmation in different senses becomes transitive. We conduct this examination both in the general case where H1 confirms H2 and in the special case where H1 also logically entails H2. Based on these analyses, we argue that (...) the Screening-Off Condition is the most important condition for transitivity in confirmation because of its generality and ease of application. We illustrate our point with the example of Moore’s ‘‘proof’’ of the existence of a material world, where H1 logically entails H2, the Screening-Off Condition holds, and confirmation in all four senses turns out to be transitive. (shrink)

My aim in this paper is to assess the viability of a perceptual epistemology based on what Anil Gupta calls the “hypothetical given”. On this account, experience alone yields no unconditional entitlement to perceptual beliefs. Experience functions instead to establish relations of rational support between what Gupta calls “views” and perceptual beliefs. I argue that the hypothetical given is a genuine alternative to the prevailing theories of perceptual justification but that the account faces a dilemma: on a natural assumption about (...) the epistemic significance of support relations, any perceptual epistemology based on the hypothetical given results in either rationalism or skepticism. I conclude by examining the prospects for avoiding the dilemma. One option is to combine the hypothetical given with a form of holism. Another is to combine the view with a form of hinge epistemology. But neither offers a simple fix. (shrink)

This book provides a philosophical framework to understand computer simulations as scientific instruments. This is in sharp contrast to existing philosophical approaches on the subject, which have historically understood computer simulations as either formal abstractions or as broadly construed empirical practices. In order to make its case, the volume contains a thorough examination of conventional philosophical approaches as well as their respective limitations. Yet, also, unlike other accounts of computer simulations from the perspective of the philosophy of science, this book (...) incorporates insights from the philosophy of technology and the history of science. Hence, the book offers philosophers of science, technologists and other researchers interested in the topic, a thorough overview of the philosophical issues regarding the design, development and deployment of computer simulations in science and science-based policy making. (shrink)

There is consensus among computer scientists, logicians, and philosophers that good reasoning with qualitative beliefs must have the structural property of cumulative transitivity or, for short, cut. This consensus is typically explicitly argued for partially on the basis of practical and mathematical considerations. But the consensus is also implicit in the approach philosophers take to almost every puzzle about reasoning that involves multiple steps: philosophers typically assume that if each step in reasoning is acceptable considered on its own, the whole (...) chain of reasoning must also acceptable. In this paper I focus on whether there are good philosophical reasons for thinking that the consensus that good reasoning must satisfy cut is true. My central claim is that we should not accept the consensus—good reasoning might not satisfy cut. In particular, I consider four arguments for the consensus and explain why they are unpersuasive. (§2-5). I then show that the issue of whether good reasoning is cut turns on a substantive yet until now unnoticed question in epistemology (§6). (shrink)

Nowadays, physicalism is arguably the received view on the nature of mental states. Among the arguments that have been provided in its favour, the inductive one seems to play a pivotal role in the debate. Leveraging the past success of materialistic science, the physicalist argues that a materialistic account of consciousness will eventually be provided, hence that physicalism is true. This article aims at evaluating whether this strategy can provide support for physicalism. According to the standard objection raised against the (...) inductive line of reasoning, the argument would beg the question by assuming some sort of metaphysical uniformity between consciousness and the rest of the natural domain. Here, I concede that there is a way to avoid this criticism. However, I argue that the argument still fails to support physicalism due to a structural problem of justification transmission. (shrink)

I argue that coherence is truth-conducive in that coherence implies an increase in the probability of truth. Central to my argument is a certain principle for transitivity in probabilistic support. I then address a question concerning the truth-conduciveness of coherence as it relates to (something else I argue for) the truth-conduciveness of consistency, and consider how the truth-conduciveness of coherence bears on coherentist theories of justification.

This paper argues that ethical propositions can legitimately be used as evidence for and against empirical conclusions. Specifically, I argue that this thesis is entailed by several uncontroversial assumptions about ethical metaphysics and epistemology. I also outline several examples of ethical-to-empirical inferences where it is extremely plausible that one can rationally rely upon their ethical evidence in order to gain a justified belief in an empirical conclusion. The main upshot is that ethical propositions can, under perfectly standard conditions, play both (...) direct and indirect evidential roles in (social) scientific inquiry. (shrink)

In this chapter I analyse an objection to phenomenal conservatism to the effect that phenomenal conservatism is unacceptable because it is incompatible with Bayesianism. I consider a few responses to it and dismiss them as misled or problematic. Then, I argue that this objection doesn’t go through because it rests on an implausible formalization of the notion of seeming-based justification. In the final part of the chapter, I investigate how seeming-based justification and justification based on one’s reflective belief that one (...) has a seeming interact with one another. (shrink)

Epistemological disjunctivists make appeal to Moorean-style anti-skeptical arguments. It is often held that one problem with using Moorean-style arguments in the context of a response to skepticism is that such arguments are subject to a kind of epistemic circularity. The specific kind of epistemic failure involved has come to be known as a failure of warrant transmission. It would likely pose a problem for the anti-skeptical ambitions of the epistemological disjunctivist if his version of the Moorean-style argument failed to transmit (...) warrant; but no epistemological disjunctivist has offered an argument to show that this is not so. In this paper, I fill the gap by arguing that warrant transmits across epistemological disjunctivist Moorean-style arguments. (shrink)

In this paper, I develop a problem I call the “Conditional Position Problem” that arises for Ernest Sosa’s externalist epistemology. The problem is that, due to a phenomenon of epistemic circularity, one is unable to attain the reflective knowledge that one is justified in believing that perception is reliable, and is confined to the merely conditional position that one is so justified if perception is reliable. The problem is similar but different from a problem that Barry Stroud has tried to (...) formulate. However, because of space limitations I cannot explain in detail what makes the two problems different. The structure of the paper is as follows: first, I explain the structural features of Sosa’s epistemology that allow the problem to arise; I also describe the normative task that is thwarted by the Conditional Position Problem; then I expound the problem itself. I proceed to examine one response that Sosa can give based on a simple inferential manoeuvre and explain why that response fails; then I examine another response he can give based on a complex form of self-support, and explain why this response also fails. I conclude explaining why the problem I present is specifically a problem for externalism. In an appendix, I very briefly describe what I take to be the main reason that justifies my claim that Stroud's problem is not the same as the problem I develop. (shrink)

In this paper, I examine Crispin Wright’s most recent attempt to introduce a diagnostic tool for predicting failures of warrant transmission, the so-called ‘Revised Template’. I show that the Revised Template does not, in fact, generate the predictions about warrant transmission failure that Wright thinks it does. I argue that the failure lies, in large part, with the definition of the technical notion ‘presupposition’ which the Revised Template deploys. Through a consideration of Wright’s own ‘general motivation’ for the Revised Template, (...) I extract an alternative characterization of ‘presupposition’ and use this to fuel a diagnostic tool for predicting failures of warrant transmission which, I believe, is both more faithful to Wright’s own general motivating remarks and more successful in predicting failures of warrant transmission than the Revised Template. (shrink)