Many epistemological problems can be solved by the objective Bayesian view that there are rationality constraints on priors, that is, inductive probabilities. But attempts to work out these constraints have run into such serious problems that many have rejected objective Bayesianism altogether. I argue that the epistemologist should borrow the metaphysician’s concept of naturalness and assign higher priors to more natural hypotheses.

Adams’s Thesis, the claim that the probabilities of indicative conditionals equal the conditional probabilities of their consequents given their antecedents, has proven impossible to accommodate within orthodox possible-world semantics. This essay proposes a modification to the orthodoxy that removes this impossibility. The starting point is a proposal by Jeffrey and Stalnaker that conditionals take semantic values in the unit interval, interpreting these (à la McGee) as their expected truth-values at a world. Their theories imply a false principle, namely, that the (...) probability of a conditional is independent of any proposition inconsistent with its antecedent. But they also point to something important, namely, that our uncertainty about conditionals is not confined to uncertainty about the facts (what the actual world is like) but also expresses uncertainty about the counterfacts (what the world would be like if one or another supposition were true). To capture this observation, this essay proposes that the semantic contents of conditionals be treated as sets of vectors of possible worlds, not singleton worlds, with the coordinates of each specifying the world that is or would be true under the supposition that it represents. The probabilities of truth for conditionals will then depend on the joint probabilities of the facts and counterfacts, the latter in turn depending on the mode of supposition. The implication of this treatment is that the probabilities of conditionals are conditional probabilities whenever the mode of supposition is evidential. (shrink)

Many who take a dismissive attitude towards metaphysics trace their view back to Carnap’s ‘Empiricism, Semantics and Ontology’. But the reason Carnap takes a dismissive attitude to metaphysics is a matter of controversy. I will argue that no reason is given in ‘Empiricism, Semantics and Ontology’, and this is because his reason for rejecting metaphysical debates was given in ‘Pseudo-Problems in Philosophy’. The argument there assumes verificationism, but I will argue that his argument survives the rejection of verificationism. The root (...) of his argument is the claim that metaphysical statements cannot be justified; the point is epistemic, not semantic. I will argue that this remains a powerful challenge to metaphysics that has yet to be adequately answered. (shrink)

The desirability of what actually occurs is often influenced by what could have been. Preferences based on such value dependencies between actual and counterfactual outcomes generate a class of problems for orthodox decision theory, the best-known perhaps being the so-called Allais Paradox. In this paper we solve these problems by extending Richard Jeffrey's decision theory to counterfactual prospects, using a multidimensional possible-world semantics for conditionals, and showing that preferences that are sensitive to counterfactual considerations can still be desirability maximising. We (...) end the paper by investigating the conditions necessary and sufficient for a desirability function to be an expected utility. It turns out that the additional conditions imply highly implausible epistemic principles. (shrink)

Sometimes we learn what the world is like, and sometimes we learn where in the world we are. Are there any interesting differences between the two kinds of cases? The main aim of this article is to argue that learning where we are in the world brings into view the same kind of observation selection effects that operate when sampling from a population. I will first explain what observation selection effects are ( Section 1 ) and how they are relevant (...) to learning where we are in the world ( Section 2 ). I will show how measurements in the Many Worlds Interpretation of quantum mechanics can be understood as learning where you are in the world via some observation selection effect ( Section 3 ). I will apply a similar argument to the Sleeping Beauty Problem ( Section 4 ) and explain what I take the significance of the analogy to be ( Section 5 ). Finally, I will defend the Restricted Principle of Indifference on which some of my arguments depend ( Section 6 ). (shrink)

This paper considers a puzzling conflict between two positions that are each compelling: it is irrational for an agent to pay to avoid `free' evidence before making a decision, and rational agents may have imprecise beliefs and/or desires. Indeed, we show that Good's theorem concerning the invariable choice-worthiness of free evidence does not generalise to the imprecise realm, given the plausible existing decision theories for handling imprecision. A key ingredient in the analysis, and a potential source of controversy, is the (...) general approach taken for resolving sequential decision problems { we make explicit what the key alternatives are and defend our own approach. Furthermore, we endorse a resolution of the aforementioned puzzle { we privilege decision theories that merely permit avoiding free evidence over decision theories for which avoiding free evidence is uniquely admissible. Finally, we situate this particular result about free evidence within the broader `dynamic-coherence' literature. (shrink)

We address a recent proposal concerning ‘surplus structure’ due to Nguyen et al.. We argue that the sense of ‘surplus structure’ captured by their formal criterion is importantly different from—and in a sense, opposite to—another sense of ‘surplus structure’ used by philosophers. We argue that minimizing structure in one sense is generally incompatible with minimizing structure in the other sense. We then show how these distinctions bear on Nguyen et al.’s arguments about Yang-Mills theory and on the hole argument.

We argue that several apparently distinct responses to the hole argument, all invoking formal or mathematical considerations, should be viewed as a unified “mathematical response.” We then consider and rebut two prominent critiques of the mathematical response before reflecting on what is ultimately at issue in this literature.

What does logic tells us how about we ought to reason? If P entails Q, and I believe P, should I believe Q? I will argue that we should embed the issue in an independently motivated contextualist semantics for ‘ought’, with parameters for a standard and set of propositions. With the contextualist machinery in hand, we can defend a strong principle expressing how agents ought to reason while accommodating conflicting intuitions. I then show how our judgments about blame and guidance (...) can be handled by this machinery. (shrink)

How should we revise our beliefs in response to the expressed probabilistic opinions of experts on some proposition when these experts are in disagreement? In this paper I examine the suggestion that in such circumstances we should adopt a linear average of the experts’ opinions and consider whether such a belief revision policy is compatible with Bayesian conditionalisation. By looking at situations in which full or partial deference to the expressed opinions of others is required by Bayesianism I show that (...) only in trivial circumstances are the requirements imposed by linear averaging compatible with it. (shrink)

Many fine-grained decisions concerning climate change involve significant, even severe, uncertainty. Here, we focus on modelling the decisions of single agents, whether individual persons or groups perceived as corporate entities. We offer a taxonomy of the sources and kinds of uncertainty that arise in framing these decision problems, as well as strategies for making a choice in spite of uncertainty. The aim is to facilitate a more transparent and structured treatment of uncertainty in climate decision making.

We introduce ‘model migration’ as a species of cross-disciplinary knowledge transfer whereby the representational function of a model is radically changed to allow application to a new disciplinary context. Controversies and confusions that often derive from this phenomenon will be illustrated in the context of econophysics and phylogeographic linguistics. Migration can be usefully contrasted with concept of ‘imperialism’, that has been influentially discussed in the context of geographical economics. In particular, imperialism, unlike migration, relies upon extension of the original model (...) via an expansion of the domain of phenomena it is taken to adequately described. The success of imperialism thus requires expansion of the justificatory sanctioning of the original idealising assumptions to a new disciplinary context. Contrastingly, successful migration involves the radical representational re-interpretation of the original model, rather than its extension. Migration thus requires ‘re-sanctioning’ of new ‘counterpart idealisations’ to allow application to an entirely different class of phenomena. Whereas legitimate scientific imperialism should be based on the pursuit of some form of ontological unification, no such requirement is need to legitimate the practice of model migration. The distinction between migration and imperialism will thus be shown to have significant normative as well as descriptive value. (shrink)

ABSTRACT In a recent article, Samir Okasha presented an argument that suggests that there is no rational way to choose among scientific theories. This would seriously undermine the view that science is a rational enterprise. In this article, I show how a suitably nuanced view of what scientific rationality requires allows us to sidestep this argument. In doing so, I present a new argument in favour of voluntarism of the type favoured by van Fraassen. I then show how such a (...) view of scientific rationality gives a precise interpretation of what Thomas Kuhn thought. _1_ Introduction _2_ Okasha’s Argument _3_ Rationality Can Be Silent _4_ Arrow Undermined _5_ The Informational-Basis Escape _6_ Theory Choice at the Level of the Individual Scientist _7_ Kuhn Vindicated _8_ Trade-offs and Partial Commensurability _9_ Conclusion. (shrink)

The Intergovernmental Panel on Climate Change has developed a novel framework for assessing and communicating uncertainty in the findings published in their periodic assessment reports. But how should these uncertainty assessments inform decisions? We take a formal decision-making perspective to investigate how scientific input formulated in the IPCC’s novel framework might inform decisions in a principled way through a normative decision model.

We give an analysis of the Monty Hall problem purely in terms of confirmation, without making any lottery assumptions about priors. Along the way, we show the Monty Hall problem is structurally identical to the Doomsday Argument.

We are living in and beyond two massive changes in the world, both of which must be addressed by education, the caretaker of memory. First is the geological era of the Anthropocene—a crisis...

Conditional attitudes are not the attitudes an agent is disposed to acquire in event of learning that a condition holds. Rather they are the components of agent's current attitudes that derive from the consideration they give to the possibility that the condition is true. Jeffrey's decision theory can be extended to include quantitative representation of the strength of these components. A conditional desirability measure for degrees of conditional desire is proposed and shown to imply that an agent's degrees of conditional (...) belief are conditional probabilities. Rational conditional preference is axiomatised and by application of Bolker's representation theorem for rational preferences it is shown that conditional preference rankings determine the existence of probability and desirability measures that agree with them. It is then proven that every conditional desirability function agrees with an agent's conditional preferences and, under certain assumptions, every desirability function agreeing with an agent's conditional preferences is a conditional desirability function agreeing with her unconditional preferences. (shrink)

Imprecise probabilities are an increasingly popular way of reasoning about rational credence. However they are subject to an apparent failure to display convincing inductive learning. This paper demonstrates that a small modification to the update rule for IP allows us to overcome this problem, albeit at the cost of satisfying only a weaker concept of coherence.

My intention is to consider Bernard Stiegler’s concept of ‘journeys of knowledge’. Open Humanities Press, 2020) and to explore how one might rethink the knowledge-creating potentialities of information itself. This has become all the more apparent in the time of lockdowns, physical distancing during the pandemic but the primary purpose of the paper is to look at the distinction between knowledge/information and the role of the teacher in using technology pharmacologically to safeguard the savoirs and to stem the proletarianization of (...) knowledge or stupidity as such. The point is that the pandemic is bringing home the question of the role of the teacher, the role of the school and the necessity of the co-production and co-creation of knowledge. It seems essential to understand the concept of ‘journeys of knowledge’ in the time of the pandemic as students are left at home without a journey to voyage upon. As such, there is a lack of futurally-bound collective protentions, an absence of any vision projection into the future. What is there in the concept of ‘journeys of knowledge’ that demonstrates how to use the Internet in bifurcatory ways, to produce what Stiegler calls negentropic knowledge or new forms of knowledge, or what I want to designate as experiments with truth-telling. What does it mean to produce negentropic knowledge without the teacher to guide, curate and care? With the above in mind, and by writing out of the wound of thinking, it is by rethinking the concept of curation in a different way that it is hoped one can contribute to educational research to produce unheard-of bifurcations of knowledge, to invoke Deleuze’s sense of the incomprehensible and Stiegler’s sense of the impossible, the improbable and the incalculable in educational concerns, to pave a path out of the aporia of the present—a present which is without decision and epoch. (shrink)

This paper uses the framework of Popper and Miller's work on axiom systems for conditional probabilities to explore Adams' thesis concerning the probabilities of conditionals. It is shown that even very weak axiom systems have only a very restricted set of models satisfying a natural generalisation of Adams' thesis, thereby casting severe doubt on the possibility of developing a non-Boolean semantics for conditionals consistent with it.

At first glance a Russian anarchist’s revolutionary address to the youth of his day made in the late 19th century and the address to youth made by a contemporary French philosopher may appear to have little in common as their context and era are ostensibly very different. How would Petr Kropotkin’s address be understood in our time? Are Kropotkin’s concerns the same as those raised by Bernard Stiegler? Could Kropotkin speak of universal concerns, a sense of elevation and sublimation not (...) governed, undermined or circumvented by digital relations, calculation or algorithmic determination? I find a mutual concern with the coming into maturity of youth, but, I am concerned that as we are passing through an epochal and revolutionary transformation driven by digital and cognitive capitalism and in our toxic and crisis-ridden milieu, Kropotkin’s rhetoric would inevitably fall on deaf ears? Is his rhetoric on revolution anachronistic? How would his rhetoric be crafted for a youth seemingly indifferent to the plight of fellow brethren? Is it conceivable that the humanist-inflected prospects of youth so vaunted by Kropotkin have now been devastated by the inhuman and nihilistic tendencies of the so-called miscreant, ‘blank generation’ as described by Stiegler? True, while it is difficult to calibrate the vision of youth affirmed in Kropotkin with the fear of youth in Stiegler, and, despite differences in episteme, tradition and political orientation, both thinkers I think are concerned with the trials and tribulations of youth and both hold out the prospect of the not-yet of youth, of the coming into being of the maturity of youth, of Aufklärung. It is this shared focus I wish to examine further. (shrink)

This article examines Becker's thesis that the hypothesis that choices maximize expected utility relative to fixed and universal tastes provides a general framework for the explanation of behaviour. Three different models of preference revision are presented and their scope evaluated. The first, the classical conditioning model, explains all changes in preferences in terms of changes in the information held by the agent, holding fundamental beliefs and desires fixed. The second, the Jeffrey conditioning model, explains them in terms of changes in (...) both the information held by the agent and changes in her prior beliefs, holding her fundamental desires fixed. The final model, that of generalized conditioning, allows for explanations in terms of changes in the values of all three variables. Key Words: preference change • decision theory • probability • desirability • attitude change. (shrink)

An important line of response to scepticism appeals to the best explanation. But anti-sceptics have not engaged much with work on explanation in the philosophy of science. I plan to investigate whether plausible assumptions about best explanations really do favour anti-scepticism. I will argue that there are ways of constructing sceptical hypotheses in which the assumptions do favour anti-scepticism, but the size of the support for anti-scepticism is small.

Models of both speech perception and speech production typically postulate a processing level that involves some form of phonological processing. There is disagreement, however, on the question of whether there are separate phonological systems for speech input versus speech output. We review a range of neuroscientific data that indicate that input and output phonological systems partially overlap. An important anatomical site of overlap appears to be the left posterior superior temporal gyrus. We then present the results of a new event‐related (...) functional magnetic resonance imaging (fMRI) experiment in which participants were asked to listen to and then (covertly) produce speech. In each participant, we found two regions in the left posterior superior temporal gyrus that responded both to the perception and production components of the task, suggesting that there is overlap in the neural systems that participate in phonological aspects of speech perception and speech production. The implications for neural models of verbal working memory are also discussed in connection with our findings. (shrink)

French philosopher Bernard Stiegler’s teacher, the great Jacques Derrida, when speaking of the nature of the life of Aristotle, questioned the need for biography and anecdote. Philosophy excludes b...

An important line of response to scepticism appeals to the best explanation. But anti-sceptics have not engaged much with work on explanation in the philosophy of science. I plan to investigate whether plausible assumptions about best explanations really do favour anti-scepticism. I will argue that there are ways of constructing sceptical hypotheses in which the assumptions do favour anti-scepticism, but the size of the support for anti-scepticism is small.

Colin Howson (1995 ) offers a counter-example to the rule of conditionalization. I will argue that the counter-example doesn't hit its target. The problem is that Howson mis-describes the total evidence the agent has. In particular, Howson overlooks how the restriction that the agent learn 'E and nothing else' interacts with the de se evidence 'I have learnt E'.

In thinking the passage from the “all-human cerebrum” to what one might call the contemporary “all-too-human” cerebrum in neo-liberal societies and beyond to the “all-too-transhuman” cerebrum in the cybernetic society, in contrasting Wells’s idea of a new world order with the dystopia of the disordering un-world, in considering the prospects of a “world brain” faced with the realities of the “global mnemotechnical system”, in highlighting the differences between the global and authoritarian instrument of “control” in Wells and the descriptions of (...) the control society by Deleuze, and finally, in critiquing the “unifying of the general intelligence services of the world” in Wells and the capturing of the “general intellect”, this paper maps the contemporary prospects of the “world brain” against the backdrop of the worldweariness of the present. (shrink)

In his recently published paper, ‘The Nature of Possibility,’ David Armstrong presents an account of possibility which, he correctly claims, is partly an elaboration of the early Wittgenstein's. Both are combinatorialists. That is to say, both hold that there is a fixed ontology of individuals, properties and relations whose combinations determine the range of all possible states of affairs, and therewith the range of all those totalities of states of affairs which they call possible worlds.But Armstrong's account, I believe, is (...) fatally flawed in ways that Wittgenstein's isn't. And this, I shall argue, is mainly because Armstrong is both an actualist, whose fixed ontology is one of actual individuals, properties and relations, and a reductionist, who tries to reduce the notion of possibility to that of ߢallߣ their combinations. Armstrong seems to think that Wittgenstein at least shares his actualism, and perhaps even his reductionism. (shrink)

Dominic Lopes proposes that seeing-in admits of kinds. He thus suggests five ways of seeing-in that he feels do justice to the variety of pictorial representations. More recently Dan Cavedon-Taylor has argued that the space of seeing-in marked out by Lopes is incomplete, and thus proposes a sixth kind of seeing-in that fits neatly into the taxonomy. I argue that the phenomenon of seeing-in does not divide in as many ways as Lopes and Cavedon-Taylor propose. I show that the purported (...) cases of pseudo-design seeing do not demonstrate that actual design properties are not experienced and as such these cases can be captured by the other ‘ways of seeing-in’ that Lopes identifies. I also argue against the claim that actualism is a distinct kind of seeing-in. Thus the space of seeing-in ought to be significantly reduced. (shrink)

It is well known that the convex hull of the classical truth value functions contains all and only the probability functions. Work by Paris and Williams has shown that this also holds for various kinds of nonclassical logics too. This note summarises the formal details of this topic and extends the results slightly.

I will argue that 'Continental Philosophy' is an Anglo-American invention. It is 'Pseudo-Continentalism,' no more than a highly selective rendering of Western European Philosophy. Borne out of opposition to the dominance of analytical philosophy in our universities, Pseudo-Continentalism in fact converges with analysis in remarkable ways. Both are advertised as revolutions in thought and both stand over against the tradition of speculative philosophy: both repeat eachother's historical shibboleths about traditional speculative philosophy in respect of the completeness of reason and of (...) reality, the priority of identity and totality, the predetermined fixity of teleology. What this amounts to is a common rejection of a chimera, which in Pseudo-Continental Philosophy is usually called onto-theology or the metaphysics of presence and in the analytic tradition is sometimes called speculative philosophy. Here, indeed, the analytic tradition is moreradical: as I will show, it characteristically rejects any notion of a special kind of activity of actualisation as a feature of the real, whether this is understood as Being, mind, will, the élan vital. Difference, or the impotential. These are the vestiges of the tradition of speculative philosophy that are retained under the rubric of Continental Philosophy. (shrink)

Many philosophers endorse the view that global or “narrative” features of a life at least partly determine its value. For instance, a life in which the subject redeems her past failures and sacrifices with later successes is thought to be better, ceteris paribus, than one in which her later successes are unrelated to her previous failures. In this paper I distinguish some views about narrative value, including Fischer’s views about the importance of free will for narrative value, and raise a (...) number of problems for the idea of narrative value. (shrink)

For each of the N-values 2, 4, 8, 16, 32, 64, 128, 256, 512, and 1,024, 50,000 samples of size N were drawn from an L-shaped population, and for each sample the Z and t statistics were calculated. The resulting distributions of 50,000 Z or t values at each sample size were then used to study the robustness of left-tailed, right-tailed, and two-tailed Z and t tests at α levels of.05,.01, and.001 (and, for Z only,.0001). The actually obtained proportion, ρ, (...) of Type I errors was often far greater or far smaller than the nominal proportion, α. Furthermore, although α is the expected value of ρ at infinite N, no N-value below 512 ever brought the deviation of p from α to within 10% of α for any t tests or one-tailed Z tests. (shrink)

Case-based reasoning is a familiar method of evaluating sentences. But when applied to conditionals, it seems to lead to implausible conclusions. In this paper I argue that the problem arises from equating the probability of a conditional sentence on the evidential supposition of some condition with the conditional probability of the former, given the latter.