Predictable polarization is everywhere: we can often predict how people’s opinions, including our own, will shift over time. Extant theories either neglect the fact that we can predict our own polarization, or explain it through irrational mechanisms. They needn’t. Empirical studies suggest that polarization is predictable when evidence is ambiguous, that is, when the rational response is not obvious. I show how Bayesians should model such ambiguity and then prove that—assuming rational updates are those which obey the value of evidence—ambiguity (...) is necessary and sufficient for the rationality of predictable polarization. The main theoretical result is that there can be a series of such updates, each of which is individually expected to make you more accurate, but which together will predictably polarize you. Polarization results from asymmetric increases in accuracy. This mechanism is not only theoretically possible, but empirically plausible. I argue that cognitive search—searching a cognitively accessible space for a particular item—often yields asymmetrically ambiguous evidence, I present an experiment supporting its polarizing effects, and I use simulations to show how it can explain two of the core causes of polarization: confirmation bias and the group polarization effect. (shrink)

Critics of contemporary metaphysics argue that it attempts to do the hard work of science from the ease of the armchair. Physics, not metaphysics, tells us about the fundamental facts of the world, and empirical psychology is best placed to reveal the content of our concepts about the world. Exploring and understanding the world through metaphysical reflection is obsolete. In this paper, I will show why this critique of metaphysics fails, arguing that metaphysical methods used to make claims about the (...) world are similar to scientific methods used to make claims about the world, but that the subjects of metaphysics are not the subjects of science. Those who argue that metaphysics uses a problematic methodology to make claims about subjects better covered by natural science get the situation exactly the wrong way around: metaphysics has a distinctive subject matter, not a distinctive methodology. The questions metaphysicians address are different from those of scientists, but the methods employed to develop and select theories are similar. In the first section of the paper, I will describe the sort of subject matter that metaphysics tends to engage with. In the second section of the paper, I will show how metaphysical theories are classes of models and discuss the roles of experience, common sense and thought experiments in the construction and evaluation of such models. Finally, in the last section I will discuss the way these methodological points help us to understand the metaphysical project. Getting the right account of the metaphysical method allows us to better understand the relationship between science and metaphysics, to explain why doing metaphysics successfully involves having a range of different theories, to understand the role of thought experiments involving fictional worlds, and to situate metaphysical realism in a scientifically realist context. (shrink)

Most philosophers of science do philosophy ‘on’ science. By contrast, others do philosophy ‘in’ science (PinS), that is, they use philosophical tools to address scientific problems and to provide scientifically useful proposals. Here, we consider the evidence in favour of a trend of this nature. We proceed in two stages. First, we identify relevant authors and articles empirically with bibliometric tools, given that PinS would be likely to infiltrate science and thus to be published in scientific journals (‘intervention’), cited in (...) scientific journals (‘visibility’), and sometimes recognized as a scientific result by scientists (‘contribution’). We show that many central figures in philosophy of science have been involved in PinS, and that some philosophers have even ‘specialized’ in this practice. Second, we propose a conceptual definition of PinS as a process involving three conditions (raising a scientific problem, using philosophical tools to address it, and making a scientific proposal), and we ask whether the articles identified at the first stage fulfil all these conditions. We show that PinS is a distinctive, quantitatively substantial trend within philosophy of science, demonstrating the existence of a methodological continuity from science to philosophy of science. (shrink)

Robert Aumann presents his Agreement Theorem as the key conditional: “if two people have the same priors and their posteriors for an event A are common knowledge, then these posteriors are equal” (Aumann, 1976, p. 1236). This paper focuses on four assumptions which are used in Aumann’s proof but are not explicit in the key conditional: (1) that agents commonly know, of some prior μ, that it is the common prior; (2) that agents commonly know that each of them updates (...) on the prior by conditionalization; (3) that agents commonly know that if an agent knows a proposition, she knows that she knows that proposition (the “K K” principle); (4) that agents commonly know that they each update only on true propositions. It is shown that natural weakenings of any one of these strong assumptions can lead to countermodels to Aumann’s key conditional. Examples are given in which agents who have a common prior and commonly know what probability they each assign to a proposition nevertheless assign that proposition unequal probabilities. To alter Aumann’s famous slogan: people can “agree to disagree”, even if they share a common prior. The epistemological significance of these examples is presented in terms of their role in a defense of the Uniqueness Thesis: If an agent whose total evidence is E is fully rational in taking doxastic attitude D to P, then necessarily, any subject with total evidence E who takes a different attitude to P is less than fully rational. (shrink)

In this essay, I discuss Dennett’s From Bacteria to Bach and Back: The Evolution of Minds and Godfrey Smith’s Other Minds: The Octopus and The Evolution of Intelligent Life from a methodological perspective. I show that these both instantiate what I call ‘synthetic philosophy.’ They are both Darwinian philosophers of science who draw on each other’s work. In what follows I first elaborate on synthetic philosophy in light of From Bacteria and Other Minds; I also explain my reasons for introducing (...) the term; and I close by looking at the function of Darwinism in contemporary synthetic philosophy. (shrink)

I identify a set of interlocking views that became (and still are) very influential within philosophy in the wake of Newton’s success. These views use the authority of natural philosophy/mechanics to settle debates within philosophy. I label these “Newton’s Challenge.”.

The expression "the marketplace of ideas" is often used in reference to Mill's views on freedom of thought and speech in On Liberty, but the metaphor does not come from Mill's work, nor is it consistent with his position. A real marketplace of ideas would create what Mill warns us against: the prevalence of the views of the most powerful and/or the most numerous. From a U.S. perspective, I explore Mill's suggestion to "countenance and encourage" minority views, and I compare (...) Mill's particular type of liberalism with contemporary U.S. advocacy of market models for our political lives. (shrink)

The main task for philosophers is introducing, clarifying, articulating, or simply redirecting concepts as—to echo Quine’s poetic formulation— “devices for working a manageable structure into the flux of experience.” I sometimes use “coining concepts” as shorthand for this task. When the concepts are quantitative they are part of a possible science ; when the concepts are qualitative they can be part of a possible philosophy. Of course, in practice, concepts are oft en stillborn, while others have multiple functions in fi (...) elds of inquiry that may straddle philosophy and science. In this chapter I argue that historians of philosophy must, among other things, coin concepts that disclose the near or distant past and create a shared horizon for our philosophical future. In virtue of our expertise we can often do so by drawing on previously orphaned concepts. The more narrow aim of this paper is to introduce two concepts, “Newton’s challenge to philosophy” and, especially, “philosophic prophecy,” that are suitable to philosophers who engage with texts in a scholarly fashion. I do so by re-telling the story of early analytical philosophy and its connection to the reception of Spinoza. By “Newton’s challenge to philosophy,” I mean the following: from about 1700 onward, “natural science” is increasingly taken to be authoritative in settling debates within philosophy; it is a concept that focuses attention on the authority of science and its various manifestations within philosophy. By “philosophic prophecy,” I mean the structured ways in which concept formation by philosophers can shape possible futures, including that of philosophy. In what follows, I first develop and characterize philosophic prophecy more precisely. In order to illuminate the concept, I contrast it with several related, more familiar concepts. Second, I offer brief critical comments on two alternative approaches to the history of philosophy promoted by Quentin Skinner and Michael Kremer in order to make more precise the approach favored here. Third, I offer a fresh narrative about the prehistory and origin of analytical philosophy. My story focuses on Ernest Nagel, who, I claim, is the philosophic prophet of analytical philosophy. Along the way, I explore the shared origins of analytical philosophy and analytical history of philosophy in the anti-Spinozistic writings of George Boole and Bertrand Russell. I oppose Nagel’s and Russell’s narratives in light of Moritz Schlick, the founder of the Vienna Circle. I adopt Schlick’s bold and unappreciated vision of the task of philosophy in scientific age. I focus on his identification of philosophical legislation with qualitative concepts. (shrink)

In this chapter we address what we call “The-Everybody-Did-It” (TEDI) Syndrome, a symptom for collective negligence. Our main thesis is that the character of scientific communities can be evaluated morally and be found wanting in terms of moral responsibility. Even an epistemically successful scientific community can be morally responsible for consequences that were unforeseen by it and its members and that follow from policy advice given by its individual members. We motivate our account by a critical discussion of a recent (...) proposal by Heather Douglas. We offer three, related criticisms of Douglas’s account. First, she assumes that scientific fields are communicative communities. Second, in a system where the scientific community autonomously sets standards, there is a danger of self-affirming reasoning. Third, she ignores that the character of a scientific community is subject to moral evaluation. We argue that these omissions in Douglas’s theory leave it with no adequate response to TEDI Syndrome. Moreover, we deny that science ought to be characterized by unanimity of belief among its competent practitioners, this leads easily to the vices of close-mindedness and expert-overconfidence. If a scientific community wishes to avoid these vices it should create conditions for an active pluralism when it and its members aspire to the position of rational policy decision-making. (shrink)

This essay takes issue with a common interpretation of Book II of Plato’s Republic as anticipating the modern theory of division of labour, first promoted by Adam Smith. It is argued that, far from anticipating Adam Smith, Plato developed original reflections which, though naturally shaped by the economic reality of his time, reveal a concern for fundamental issues of economic thought: the value of labour, the nature of economic interdependence in a political association, the relation between economic behaviour and justice. (...) However, despite having recognized some of the fundamental forces behind human economic behaviour, Plato ends up with an envisioned ideal state in which those forces are given no scope, for he makes no room for economic competitiveness and technological advancement. (shrink)

Not much is known about Prodicus of Ceos, though he is mentioned in more than a dozen Platonic dialogues and appears as a character in the Protagoras. In this article I examine the extant evidence about Prodicus from Plato and other ancient authors and show that Plato's attitude toward him was, surprisingly, one of great respect. In fact, Plato suggests that Prodicus was quite literally Socrates' teacher. I argue that by considering the evidence carefully we can determine with some confidence (...) what Socrates probably took from his instruction, namely, an art of making careful distinctions (diairesis), which had important political and philosophical applications. (shrink)