There is a theorem that shows that it is impossible for an algorithm to jointly satisfy the statistical fairness criteria of Calibration and Equalised Odds non-trivially. But what about the recently advocated alternative to Calibration, Base Rate Tracking? Here, we show that Base Rate Tracking is strictly weaker than Calibration, and then take up the question of whether it is possible to jointly satisfy Base Rate Tracking and Equalised Odds in non-trivial scenarios. We show that it is not, thereby establishing (...) an even more general impossibility theorem. (shrink)

Guthrie contends that religion can best be understood as systematic anthropomorphism - the attribution of human characteristics to nonhuman things and events. Religion, he says, consists of seeing the world as human like. He offers a fascinating array of examples to show how this strategy pervades secular life and how it characterizes religious experience.

In this paper, I discuss how Nietzsche’s critique of nihilism concerns the complicity between Christian morality and modern atheism. I unpack in what sense Schopenhauer’s ascetic denial of the will signifies a return to nothingness, what he calls the nihil negativum. I argue that Nietzsche’s formulation of nihilism specifically targets Schopenhauer’s pessimism as the culmination of the Western metaphysical tradition, the crucial stage of its intellectual history in which the scientific pursuit of truth finally unveils the ascetic will to nothingness (...) that motivates it. I contend that Nietzsche’s critique of Schopenhauer anticipates current scholarly debates around the significance of the nihil negativum and offers a compelling objection against contemporary proponents of philosophical nihilism such as Eugene Thacker and Ray Brassier. (shrink)

Hofweber (Ontology and the ambitions of metaphysics, Oxford University Press, 2016) argues for a thesis he calls “internalism” with respect to natural number discourse: no expressions purporting to refer to natural numbers in fact refer, and no apparent quantification over natural numbers actually involves quantification over natural numbers as objects. He argues that while internalism leaves open the question of whether other kinds of abstracta exist, it precludes the existence of natural numbers, thus establishing what he calls “restricted nominalism” about (...) natural numbers. We argue that Hofweber’s internalism fails to establish restricted nominalism. Not only is his primary argument for restricted nominalism invalid, the analysis of quantification proposed threatens to collapse internalism into either a traditional form of error theory or realism. (shrink)

Draft for the Oxford Handbook of Margaret Cavendish (edited by Julie Crawford with Jacqueline Broad). -/- This chapter looks at Margaret Cavendish's treatment of the supernatural, beginning by asking how she distinguishes the natural from the supernatural, and then by examining her treatment of a series of alleged supernatural beings: fairies, ghosts, witches, the human supernatural soul, angels, and God. Throughout, it argues that Cavendish's approach to the supernatural is often similar to Thomas Hobbes's.

In the _True Intellectual System_, Cudworth attacks types of atheist position—atomic atheism, hylozoic atheism, etc. He generally uses ancient examples to illustrate those types, but also criticizes some of his contemporaries. We can identify direct criticisms of contemporaries by finding quotations, paraphrases, and accounts of their views in the text. My primary question in this paper is, 'how much of the _True Intellectual System_ is directly about or aimed at Spinoza?' My ultimate answer, contrary to some prominent voices in the (...) existing literature, is 'not very much at all'. (shrink)

In many assessment problems—aptitude testing, hiring decisions, appraisals of the risk of recidivism, evaluation of the credibility of testimonial sources, and so on—the fair treatment of different groups of individuals is an important goal. But individuals can be legitimately grouped in many different ways. Using a framework and fairness constraints explored in research on algorithmic fairness, I show that eliminating certain forms of bias across groups for one way of classifying individuals can make it impossible to eliminate such bias across (...) groups for another way of dividing people up. And this point generalizes if we require merely that assessments be approximately bias-free. Moreover, even if the fairness constraints are satisfied for some given partitions of the population, the constraints can fail for the coarsest common refinement, that is, the partition generated by taking intersections of the elements of these coarser partitions. This shows that these prominent fairness constraints admit the possibility of forms of intersectional bias. (shrink)

When trust is broken, how should we determine who is at fault? Previous discus- sions of broken trust typically attribute the fault to trusters who place trust foolishly or trustees who act in an untrustworthy manner. These discussions take for granted the ability of the truster and trustee to communicate and understand the boundaries of what is being entrusted, that is, the domain of trust. However, the boundaries of entrusted domains are not always clear to either party which can result (...) in broken trust despite the best efforts of both truster and trustee. In this paper, I argue that deter- mining who to blame when trust is broken is a messy affair in which disagreements over fault regularly arise. I introduce three features of trust domains that take center stage in negotiations regarding who is at fault when trust is broken: scope, rigidity and ordering. (shrink)

The traditional view in epistemology is that we must distinguish between being rational and being right (that is also, by the way, the traditional view about practical rationality). In his paper in this volume, Williamson proposes an alternative view according to which only beliefs that amount to knowledge are rational (and, thus, no false belief is rational). It is healthy to challenge tradition, in philosophy as much as elsewhere. But, in this instance, we think that tradition has it right. In (...) this paper we defend our version of the traditional view and argue against Williamson’s alternative. (shrink)

Recent impossibility theorems for fair risk assessment extend to the domain of epistemic justice. We translate the relevant model, demonstrating that the problems of fair risk assessment and just credibility assessment are structurally the same. We motivate the fairness criteria involved in the theorems as also being appropriate in the setting of testimonial justice. Any account of testimonial justice that implies the fairness/justice criteria must be abandoned, on pain of triviality.

I consider statistical criteria of algorithmic fairness from the perspective of the _ideals_ of fairness to which these criteria are committed. I distinguish and describe three theoretical roles such ideals might play. The usefulness of this program is illustrated by taking Base Rate Tracking and its ratio variant as a case study. I identify and compare the ideals of these two criteria, then consider them in each of the aforementioned three roles for ideals. This ideals program may present a way (...) forward in the normative evaluation of candidate statistical criteria of algorithmic fairness. (shrink)

I provide a characterization of weakly pseudo-rationalizable choice functions---that is, choice functions rationalizable by a set of acyclic relations---in terms of hyper-relations satisfying certain properties. For those hyper-relations Nehring calls extended preference relations, the central characterizing condition is weaker than (hyper-relation) transitivity but stronger than (hyper-relation) acyclicity. Furthermore, the relevant type of hyper-relation can be represented as the intersection of a certain class of its extensions. These results generalize known, analogous results for path independent choice functions.

Timothy Williamson has fruitfully exploited formal resources to shed considerable light on the nature of knowledge. In the paper under examination, Williamson turns his attention to Gettier cases, showing how they can be motivated formally. At the same time, he disparages the kind of justification he thinks gives rise to these cases. He favors instead his own notion of justification for which Gettier cases cannot arise. We take issue both with his disparagement of the kind of justification that figures in (...) Gettier cases and the specifics of the formal motivation. (shrink)

Our aim here is to present a result that connects some approaches to justifying countable additivity. This result allows us to better understand the force of a recent argument for countable additivity due to Easwaran. We have two main points. First, Easwaran’s argument in favour of countable additivity should have little persuasive force on those permissive probabilists who have already made their peace with violations of conglomerability. As our result shows, Easwaran’s main premiss – the comparative principle – is strictly (...) stronger than conglomerability. Second, with the connections between the comparative principle and other probabilistic concepts clearly in view, we point out that opponents of countable additivity can still make a case that countable additivity is an arbitrary stopping point between finite and full additivity. (shrink)

This paper generalizes rationalizability of a choice function by a single acyclic binary relation to rationalizability by a set of such relations. Rather than selecting those options in a menu that are maximal with respect to a single binary relation, a weakly pseudo-rationalizable choice function selects those options that are maximal with respect to at least one binary relation in a given set. I characterize the class of weakly pseudo-rationalizable choice functions in terms of simple functional properties. This result also (...) generalizes Aizerman and Malishevski's characterization of pseudo-rationalizable choice functions, that is, choice functions rationalizable by a set of total orders. (shrink)

Saul Kripke once noted that there is a tight connection between computation and de re knowledge of whatever the computation acts upon. For example, the Euclidean algorithm can produce knowledge of which number is the greatest common divisor of two numbers. Arguably, algorithms operate directly on syntactic items, such as strings, and on numbers and the like only via how the numbers are represented. So we broach matters of notation. The purpose of this article is to explore the relationship between (...) the notations acceptable for computation, the usual idealizations involved in theories of computability, flowing from Alan Turing’s monumental work, and de re propositional attitudes toward numbers and other mathematical objects. (shrink)

Merging of opinions results underwrite Bayesian rejoinders to complaints about the subjective nature of personal probability. Such results establish that sufficiently similar priors achieve consensus in the long run when fed the same increasing stream of evidence. Initial subjectivity, the line goes, is of mere transient significance, giving way to intersubjective agreement eventually. Here, we establish a merging result for sets of probability measures that are updated by Jeffrey conditioning. This generalizes a number of different merging results in the literature. (...) We also show that such sets converge to a shared, maximally informed opinion. Convergence to a maximally informed opinion is a (weak) Jeffrey conditioning analogue of Bayesian “convergence to the truth” for conditional probabilities. Finally, we demonstrate the philosophical significance of our study by detailing applications to the topics of dynamic coherence, imprecise probabilities, and probabilistic opinion pooling. (shrink)

In the face of an impossibility result, some assumption must be relaxed. The Mere Addition Paradox is an impossibility result in population ethics. Here, I explore substantially weakening the decision-theoretic assumptions involved. The central finding is that the Mere Addition Paradox persists even in the general framework of choice functions when we assume Path Independence as a minimal decision-theoretic constraint. Choice functions can be thought of either as generalizing the standard axiological assumption of a binary “betterness” relation, or as providing (...) a general framework for a normative (rather than axiological) theory of population ethics. Path Independence, a weaker assumption than typically (implicitly) made in population ethics, expresses the idea that, in making a choice from a set of alternatives, the order in which options are assessed or considered is ethically arbitrary and should not affect the final choice. Since the result establishes a conflict between the relevant ethical principles and even very weak decision-theoretic principles, we have more reason to doubt the ethical principles. (shrink)

In his Enquiry concerning the Principles of Morals David Hume said that a group of earlier modern philosophers, beginning with Malebranche, held that morality was founded on relations. In this paper I follow up on that suggestion by investigating pre-Humean views in moral philosophy according to which morality is founded on relations. I do that by looking at the work of Nicolas Malebranche, John Locke, and Samuel Clarke. Each of them talked prominently about relations in their accounts of basic aspects (...) of morality. Beyond that, each of them turns out to have held both metaphysical and epistemological views that might be described as founding morality on relations. Despite the definite differences between the three philosophers’ approaches, Hume does seem to have noticed a genuine connection here—even though he himself tended to ignore significant versions of this approach when criticizing it. (shrink)

Thomas Hobbes often includes powers and abilities in his descriptions of the world. Meanwhile, Hobbes’s philosophical picture of the world appears quite reductive, and he seems sometimes to say that nothing exists but bodies in motion. In more extreme versions of such a picture, there would be no room for powers. Hobbes is not an eliminativist about powers, but his view does tend toward ontological minimalism. It would be good to have an account of what Hobbes thinks powers are, and (...) how they fit into his understanding of the world. In this chapter, I investigate Hobbes’s account of the metaphysics of powers and abilities. Section 1 considers three important aspects of Hobbes’s account of powers: the connection between powers and causes; the modal aspects of powers; and the connection between powers and motions. Sections 2 and 3 then consider interpretive arguments about whether Hobbes identifies powers with underlying corporeal features. (shrink)

This paper investigates Locke’s views about materialism, by looking at the discussion in Essay IV.x. There Locke---after giving a cosmological argument for the existence of God---argues that God could not be material, and that matter alone could never produce thought. In discussing the chapter, I pay particular attention to some comparisons between Locke’s position and those of two other seventeenth-century philosophers, René Descartes and Ralph Cudworth. -/- Making use of those comparisons, I argue for two main claims. The first is (...) that the important argument of Essay IV.x.10 is fundamentally an argument about the causation of perfections. Indeed, Locke gives multiple such arguments in the chapter. My second main claim is that my proposed reading of IV.x is not merely consistent with what Locke says elsewhere about superaddition, but also provides reasons to favor a particular understanding of what superaddition is. (shrink)

In his Target Article, Terrence Deacon develops simple models that assist in understanding the role of RNA in the origins of life. However, his models fail to adequately represent an important evolutionary dynamic. Central to this dynamic is the selection that impinges on RNA molecules in the context of their association with proto-metabolisms. This selection shapes the role of RNA in the emergence of life. When this evolutionary dynamic is appropriately taken into account, it predicts a role for RNA that (...) is consistent with the Managed-Metabolism Hypothesis about the origins of life, and inconsistent with Deacon’s account. (shrink)

This paper discusses the materialist views of Margaret Cavendish, focusing on the relationships between her views and those of two of her contemporaries, Thomas Hobbes and Henry More. It argues for two main claims. First, Cavendish's views sit, often rather neatly, between those of Hobbes and More. She agreed with Hobbes on some issues and More on others, while carving out a distinctive alternative view. Secondly, the exchange between Hobbes, More, and Cavendish illustrates a more general puzzle about just what (...) divided materialists from their opponents. Seemingly straightforward disagreements about whether incorporeal substances exist turn out to be more complex ones in which the nature of those things is disputed at the same time as their existence. (shrink)

The evolution of life on Earth has produced an organism that is beginning to model and understand its own evolution and the possible future evolution of life in the universe. These models and associated evidence show that evolution on Earth has a trajectory. The scale over which living processes are organized cooperatively has increased progressively, as has its evolvability. Recent theoretical advances raise the possibility that this trajectory is itself part of a wider developmental process. According to these theories, the (...) developmental process has been shaped by a yet larger evolutionary dynamic that involves the reproduction of universes. This evolutionary dynamic has tuned the key parameters of the universe to increase the likelihood that life will emerge and produce outcomes that are successful in the larger process (e.g. a key outcome may be to produce life and intelligence that intentionally reproduces the universe and tunes the parameters of ‘offspring’ universes). Theory suggests that when life emerges on a planet, it moves along this trajectory of its own accord. However, at a particular point evolution will continue to advance only if organisms emerge that decide to advance the developmental process intentionally. The organisms must be prepared to make this commitment even though the ultimate nature and destination of the process is uncertain, and may forever remain unknown. Organisms that complete this transition to intentional evolution will drive the further development of life and intelligence in the universe. Humanity’s increasing understanding of the evolution of life in the universe is rapidly bringing it to the threshold of this major evolutionary transition. (shrink)

This chapter looks at the discussion of materialism in John Locke’s Essay concerning Human Understanding, and then at parts of the Anglophone reaction to those discussions. It considers the early criticisms of Locke by Edward Stillingfleet and the anonymous author of three sets of Remarks on Locke’s Essay. It then looks at some other ways in which readers reacted to Locke’s discussions: the views of Anthony Collins and John Toland, which one might be tempted to think of as Lockean materialism; (...) William Carroll’s reading of Locke as a Spinozistic materialist; and the dualistic Lockeanism of William Duncan’s Lockean logic textbook. (shrink)

Humans are able to construct mental representations and models of possible interactions with their environment. They can use these mental models to identify actions that will enable them to achieve their adaptive goals. But humans do not use this capacity to identify and implement the actions that would contribute most to the evolutionary success of humanity. In general, humans do not find motivation or satisfaction in doing so, no matter how effective such actions might be in evolutionary terms. From an (...) evolutionary perspective, this is a significant limitation in the psychological adaptability of humans. This paper sets out to identify the new psychological capacity that would be needed to overcome this limitation and how the new capacity might be acquired. Humans that develop this capacity will become self-evolving organisms - organisms that are able to adapt in whatever ways are necessary for future evolutionary success, largely unfettered by their biological and social past. (shrink)

Leibniz's mill argument in 'Monadology' 17 is a well-known but puzzling argument against materialism about the mind. I approach the mill argument by considering other places where Leibniz gave similar arguments, using the same example of the machinery of a mill and reaching the same anti-materialist conclusion. In a 1702 letter to Bayle, Leibniz gave a mill argument that moves from his definition of perception (as the expression of a multitude by a simple) to the anti-materialist conclusion. Soon afterwards, in (...) the Preface to the New Essays, Leibniz gave a different mill argument. That argument depends upon there being no arbitrary and inexplicable connections in nature, because God would not create such things. Later, in the 'Monadology', Leibniz again used the mill example in arguing against materialism. That passage too, I argue, uses an argument from inexplicability rather than from Leibniz's definition of perception. (shrink)

In the early years of the eighteenth century Leibniz had several interactions with John Toland. These included, from 1702 to 1704, discussions of materialism. Those discussions culminated with the consideration of Toland's 1704 Letters to Serena, where Toland argued that matter is necessarily active. In this paper I argue for two main theses about this exchange and its consequences for our wider understanding. The first is that, despite many claims that Toland was at the time of Letters to Serena a (...) Spinozist, we can make better sense of him as a sort of Hobbesian materialist. The second main point concerns reasons for materialism, and in particular a story Locke tells in the Essay about materialists' motives. Toland defends his materialism by arguing that matter is active, and argues that matter is active by using a conceivability argument. But this is not the crude conceivability argument that Locke suggests motivates materialists. This (together with reflecting on some of Hobbes's arguments) suggests that we might well tell a Lockean story about reasons for early modern materialism, but not Locke's story. (shrink)

The ‘managed-metabolism’ hypothesis suggests that a ‘cooperation barrier’ must be overcome if self-producing chemical organizations are to undergo the transition from non-life to life. This dynamical barrier prevents un-managed autocatalytic networks of molecular species from individuating into complex, cooperative organizations. The barrier arises because molecular species that could otherwise make significant cooperative contributions to the success of an organization will often not be supported within the organization, and because side reactions and other ‘free-riding’ processes will undermine cooperation. As a result, (...) the barrier seriously impedes the emergence of individuality, complex functionality and the transition to life. This barrier is analogous to the cooperation barrier that also impedes the emergence of complex cooperation at all levels of living organization. As has been shown at other levels of organization, the barrier can be overcome comprehensively by appropriate ‘management’. Management implements a system of evolvable constraints that can overcome the cooperation barrier by ensuring that beneficial co-operators are supported within the organization and by suppressing free-riders. In this way, management can control and manipulate the chemical processes of a collectively autocatalytic organization, producing novel processes that serve the interests of the organization as a whole and that could not arise and persist in an un-managed chemical organization. Management self-organizes because it is able to capture some of the benefits that are produced when its interventions promote cooperation, thereby enhancing productivity. Selection will therefore favour the emergence of managers that take over and manage chemical organizations so as to overcome the cooperation barrier. The managed-metabolism hypothesis demonstrates that if management is to overcome the cooperation barrier comprehensively, its interventions must be digitally coded. In this way, the hypothesis accounts for the two-tiered structure of all living cells in which a digitally-coded genetic apparatus manages an analogically-informed metabolism.GraphicalOpen image in new window. (shrink)

I argue that Hobbes isn't really a materialist in the early 1640s (in, e.g., the Third Objections to Descartes's Meditations). That is, he doesn't assert that bodies are the only substances. However, he does think that bodies are the only substances we can think about using imagistic ideas.

Hobbes denies in Leviathan that we have an idea of God. He does think, though, that God exists, and does not even deny that we can think about God, even though he says we have no idea of God. There is, Hobbes thinks, another cognitive mechanism by means of which we can think about God. That mechanism allows us only to think a few things about God though. This constrains what Hobbes can say about our knowledge of God, and grounds (...) his belief in a fairly strong version of the thesis that God is incomprehensible. (shrink)

An aspect of Peirce’s thought that may still be underappreciated is his resistance to what Levi calls _pedigree epistemology_, to the idea that a central focus in epistemology should be the justification of current beliefs. Somewhat more widely appreciated is his rejection of the subjective view of probability. We argue that Peirce’s criticisms of subjectivism, to the extent they grant such a conception of probability is viable at all, revert back to pedigree epistemology. A thoroughgoing rejection of pedigree in the (...) context of probabilistic epistemology, however, _does_ challenge prominent subjectivist responses to the problem of the priors. (shrink)

We introduce a fairness criterion that we call Spanning. Spanning i) is implied by Calibration, ii) retains interesting properties of Calibration that some other ways of relaxing that criterion do not, and iii) unlike Calibration and other prominent ways of weakening it, is consistent with Equalized Odds outside of trivial cases.

Epistemic states of uncertainty play important roles in ethical and political theorizing. Theories that appeal to a “veil of ignorance,” for example, analyze fairness or impartiality in terms of certain states of ignorance. It is important, then, to scrutinize proposed conceptions of ignorance and explore promising alternatives in such contexts. Here, I study Lerner’s probabilistic egalitarian theorem in the setting of imprecise probabilities. Lerner’s theorem assumes that a social planner tasked with distributing income to individuals in a population is “completely (...) ignorant” about which utility functions belong to which individuals. Lerner models this ignorance with a certain uniform probability distribution, and shows that, under certain further assumptions, income should be equally distributed. Much of the criticism of the relevance of Lerner’s result centers on the representation of ignorance involved. Imprecise probabilities provide a general framework for reasoning about various forms of uncertainty including, in particular, ignorance. To what extent can Lerner’s conclusion be maintained in this setting? (shrink)

The notion of signification is an important part of Hobbes's philosophy of language. It also has broader relevance, as Hobbes argues that key terms used by his opponents are insignificant. However Hobbes's talk about names' signification is puzzling, as he appears to have advocated conflicting views. This paper argues that Hobbes endorsed two different views of names' signification in two different contexts. When stating his theoretical views about signification, Hobbes claimed that names signify ideas. Elsewhere he talked as if words (...) signified the things they named. Seeing this does not just resolve a puzzle about Hobbes's statements about signification. It also helps us to understand how Hobbes's arguments about insignificant speech work. With one important exception, they depend on the view that names signify things, not on Hobbes's stated theory that words signify ideas. The paper concludes by discussing whether arguments about insignificant speech can provide independent support for Hobbes's views about other issues, such as materialism. (shrink)

Leibniz frequently uses the notion of expression, but it is not easy to see just how he understood that relation. This paper focuses on the particular case of the expression of God, which is prominent in the 'Discourse on Metaphysics'. The treatment of expression there suggests several questions. Which substances did Leibniz believe expressed God? Why did Leibniz believe those substances expressed God? And did he believe that all substances expressed God in the same way and for the same reasons? (...) In answering those questions the paper distinguishes two views about expression in the 'Discourse', considers Leibniz's reasons for holding that substances express their causes, and argues that Leibniz's views about emanative causation are important for understanding the unity of his apparently distinct views here. The paper concludes by looking briefly at how the 'Discourse' fits into the evolution of Leibniz's views on this issue over time. (shrink)

In this article, I argue that Immanuel Kant fails to provide a satisfactory account of ‘moral debt’ in Religion within the Boundaries of Mere Reason. More precisely, he fails to answer the question of why we should assume that a debt exists in the first place. In light of recent scholarship on this area of his thought, I sketch some possible readings of Kant on the nature of moral transformation that suggest how he might account for this debt. I then (...) argue that these accounts fail to justify its existence within Kant's project. (shrink)

Bayesians often appeal to “merging of opinions” to rebut charges of excessive subjectivity. But what happens in the short run is often of greater interest than what happens in the limit. Seidenfeld and coauthors use this observation as motivation for investigating the counterintuitive short run phenomenon of dilation, since, they allege, dilation is “the opposite” of asymptotic merging of opinions. The measure of uncertainty relevant for dilation, however, is not the one relevant for merging of opinions. We explicitly investigate the (...) short run behavior of the metric relevant for merging, and show that dilation is independent of the opposite of merging. (shrink)

This chapter considers Ralph Cudworth as a philosophical critic of Hobbes. Cudworth saw Hobbes as a representative of the three views he was attacking: atheism, determinism, and the denial that morality is eternal and immutable. Moreover, he did not just criticize Hobbes by assuming that a general critique of those views applied to Hobbes’s particular case. Rather, he singled out Hobbes, often by quoting him, and argued against the distinctively Hobbesian positions he had identified. In this chapter I look at (...) Cudworth as a critic of Hobbes in two of the three central areas, atheism and ethics, focusing on passages where we see him explicitly picking out Hobbes. (shrink)

We look at some interesting and important episodes in the life of early modern Epicureanism, focusing on natural philosophy. We begin with two early moderns who had a great deal to say about ancient Epicureanism: Pierre Gassendi and Ralph Cudworth. Looking at how Gassendi and Cudworth conceived of Epicureanism gives us a sense of what the early moderns considered important in the ancient tradition. It also points us towards three main themes of early modern Epicureanism in natural philosophy, which we (...) then discuss at greater length: atomism, materialism about the mind or soul, and the denial of providence, which was often accompanied by deflationary explanations of religious belief. (shrink)

Language was central to Hobbes's understanding of human beings and their mental abilities, and criticism of other philosophers' uses of language became a favorite critical tool for him. This paper connects Hobbes's theories about language to his criticisms of others' language, examining Hobbes's theories of propositions and truth, and how they relate to his claims that various sorts of proposition are absurd. It considers whether Hobbes in fact means anything more by 'absurd' than 'false'. And it pays particular attention to (...) Hobbes's categorization of causes of absurdity and of types of incoherent proposition, arguing that Hobbes's approach is only loosely related to later discussions of category mistakes. (shrink)

Does the Big History of life on Earth disclose a trajectory that has been driven by selection? If so, will the trajectory continue to apply into the future? This paper argues that such a trajectory exists, and examines some of its key implications. The most important consequence is that humanity can use the trajectory to guide how it evolves and adapts into the future. This is because the trajectory identifies a sequence of adaptations that will be favoured by selection. If (...) humanity intentionally evolves its social systems and psychological capacities so that they follow the trajectory, humanity can avoid negative selection and instead survive and thrive indefinitely into the future. This would enable humanity to make a positive contribution to the future evolution of life in the universe. But it turns out that immediate selection will not drive the evolution of life on Earth further along this trajectory. Instead, intentional action by humanity is necessary. It is as if the evolution of life on any planet is a developmental process that has a very unusual characteristic: evolution will continue to develop successfully beyond a certain point only if it produces a sentient organism that: (i) awakens to the possibility it is embedded in a developing process; (ii) realizes that this developing process will continue successfully only if it chooses to intentionally drive the process forward; and (iii) commits to doing whatever is necessary to achieve this. On this planet, humanity is that sentient organism. The existence of such a key evolutionary role for humanity is capable of providing humanity with meaning and purpose in a larger scheme of things. For individuals who commit to driving the process forward, the nature of the trajectory has immediate consequences for what they should do with their lives, here and now. (shrink)

I consider Leibniz's thoughts about Hobbes's materialism, focusing on his less-discussed later thoughts about the topic. Leibniz understood Hobbes to have argued for his materialism from his imagistic theory of ideas. Leibniz offered several criticisms of this argument and the resulting materialism itself. Several of these criticisms occur in texts in which Leibniz was engaging with the generation of British philosophers after Hobbes. Of particular interest is Leibniz's correspondence with Damaris Masham. Leibniz may have been trying to communicate with Locke, (...) but ended up discussing Masham's version of the argument for materialism that Leibniz attributed to Hobbes. (shrink)

Gassendi and Hobbes knew each other, and their approaches to philosophy often seem similar. They both criticized the Cartesian epistemology of clear and distinct perception. Gassendi engaged at length with skepticism, and also rejected the Aristotelian notion of scientia, arguing instead for a probabilistic view that shows us how we can move on in the absence of certain and evident knowledge. Hobbes, in contrast, retained the notion of scientia, which is the best sort of knowledge and involves causal explanation. He (...) thought, however, that this sort of knowledge was only available in geometry and political philosophy. (shrink)

Supra-Bayesianism is the Bayesian response to learning the opinions of others. Probability pooling constitutes an alternative response. One natural question is whether there are cases where probability pooling gives the supra-Bayesian result. This has been called the problem of Bayes-compatibility for pooling functions. It is known that in a common prior setting, under standard assumptions, linear pooling cannot be nontrivially Bayes-compatible. We show by contrast that geometric pooling can be nontrivially Bayes-compatible. Indeed, we show that, under certain assumptions, geometric and (...) Bayes-compatible pooling are equivalent. Granting supra-Bayesianism its usual normative status, one upshot of our study is thus that, in a certain class of epistemic contexts, geometric pooling enjoys a normative advantage over linear pooling as a social learning mechanism. We discuss the philosophical ramifications of this advantage, which we show to be robust to variations in our statement of the Bayes-compatibility problem. (shrink)

Early modern debates about the nature of matter interacted with debates about whether matter could think. In particular, some philosophers (e.g., Cudworth and Leibniz) objected to materialism about the human mind on the grounds that matter is passive, thinking things are active, and one cannot make an active thing out of passive material. This paper begins by looking at two seventeenth-century materialist views (Hobbes’s, and one suggested but not endorsed by Locke) before considering that objection (which I call here the (...) Activity Argument). In discussion, I note that several philosophers of the time believed that matter was active. That view opens up a possible response to the Activity Argument. The paper concludes by looking at the views of two materialists of the time who also believed that matter was active, Toland and Cavendish. (shrink)

Evolution's Arrow argues that evolution is directional and progressive, and that this has major consequences for humanity. Without resort to teleology, the book demonstrates that evolution moves in the direction of producing cooperative organisations of greater scale and evolvability - evolution has organised molecular processes into cells, cells into organisms, and organisms into societies. The book founds this position on a new theory of the evolution of cooperation. It shows that self-interest at the level of the genes does not prevent (...) cooperation from increasing as evolution unfolds. Evolution progresses by discovering ways to build cooperative organisations out of self-interested individuals. The book also shows that evolution itself has evolved. Evolution has progressively improved the ability of evolutionary mechanisms to discover effective adaptations. And it has produced new and better mechanisms. Evolution's Arrow uses this understanding of the direction of evolution to identify the next great steps in the evolution of life on earth - the steps that humanity must take if we are to continue to be successful in evolutionary terms. A key step for humanity is to increase the scale and evolvability of our societies, eventually forming a unified and cooperative society on the scale of the planet. We must also transform ourselves psychologically to become self-evolving organisms - organisms that are able to escape their biological and cultural past by adapting in whatever directions are necessary to achieve future evolutionary success. (shrink)

James Van Cleve raises some objections to my attempt to solve the bootstrapping problem for what I call “basic justification theories.” I argue that given 1 the inference rules endorsed by basic justification theorists, we are a priori (propositionally) justified in believing that perception is reliable. This blocks the bootstrapping result.