This article shows that there is a liar-like paradox that arises for rational credence that relies only on very weak logical and credal principles. The paradox depends on a weak rational reflection principle, logical principles governing conjunction, and principles governing the relationship between rational credence and proof. To respond to this paradox, we must either reject even very weak rational reflection principles or reject some highly plausible logical or credal principle.

This paper explores an initially attractive principle connecting beliefs in general with beliefs about what beliefs are rational. The principle turns out to be violated by intuitively rational beliefs in some situations. The paper lays out some options for reacting to this fact.

One recent topic of debate in Bayesian epistemology has been the question of whether imprecise credences can be rational. I argue that one account of imprecise credences, the orthodox treatment as defended by James M. Joyce, is untenable. Despite Joyce’s claims to the contrary, a puzzle introduced by Roger White shows that the orthodox account, when paired with Bas C. van Fraassen’s Reflection Principle, can lead to inconsistent beliefs. Proponents of imprecise credences, then, must either provide a (...) compelling reason to reject Reflection or admit that the rational credences in White’s case are precise. (shrink)

The much-debated Reflection principle states that a coherent agent’s cre- dences must match their estimates for their future credences. Defenders claim that there are Dutch-book arguments in its favor, putting it on the same normative footing as probabilistic coherence. Critics claim that those arguments rely on the implicit, implausible assumption that the agent is introspective: that they are certain what their own credences are. In this paper, we clarify this debate by surveying several different concep- tions of the (...) book scenario. We show that the crucial disagreement hinges on whether agents who are not introspective are known to reliably act on their credences: if they are, then coherent Reflection failures are (at best) ephemeral; if they aren’t, then Reflection failures can be robust— and perhaps rational and coherent. We argue that the crucial question for future debates is which notion of coherence makes sense for such unreliable agents, and sketch a few avenues to explore. (shrink)

How far, if at all, do our intrapersonal and our interpersonal epistemic obligations run in parallel? This paper treats the question as addressing the stability of doxastic commitment in the two dimensions. In the background lies an analogy between doxastic and practical commitment. We’ll pursue the question of doxastic stability by coining a doxastic analogue of Gregory Kavka’s much-discussed toxin case. In this new case, you foresee that you will rationally abandon a doxastic commitment by undergoing a shift in the (...) context in which you doxastically deliberate. The case reveals an important stability condition on doxastic commitment that plays no role in cases modeled on Ulysses and the Sirens, the scenario that has shaped previous attempts to draw an analogy between doxastic and practical commitment. The stability condition thereby revealed is not diachronic -- it does not involve a shift in belief -- but we can construct specifically diachronic cases that reveal an important intrapersonal epistemic obligation. This obligation arises when you expect the shift in belief by ‘projecting’ yourself into a future doxastic context -- thus vindicating a restricted, but only this restricted, application of Bas van Fraassen’s Reflection Principle. Despite some important differences, we can use these diachronic cases as a model for interpersonal cases that reveal an important role for doxastic context in the epistemology of disagreement. But the roles played by projection and context in disagreement ensure that there is no general obligation to be responsive to the opinion of an epistemic peer who disagrees with you. (shrink)

We discuss the cable guy paradox, both as an object of interest in its own right and as something which can be used to illuminate certain issues in the theories of rational choice and belief. We argue that a crucial principle—The Avoid Certain Frustration (ACF) principle—which is used in stating the paradox is false, thus resolving the paradox. We also explain how the paradox gives us new insight into issues related to the Reflection principle. Our (...) general thesis is that principles that base your current opinions on your current opinions about your future opinions need not make reference to the particular times in the future at which you believe you will have those opinions, but they do need to make reference to the particular degrees of belief you believe you will have in the future. (shrink)

I advocate Time-Slice Rationality, the thesis that the relationship between two time-slices of the same person is not importantly different, for purposes of rational evaluation, from the relationship between time-slices of distinct persons. The locus of rationality, so to speak, is the time-slice rather than the temporally extended agent. This claim is motivated by consideration of puzzle cases for personal identity over time and by a very moderate form of internalism about rationality. Time-Slice Rationality conflicts with two proposed principles (...) of rationality, Conditionalization and Reflection. Conditionalization is a diachronic norm saying how your current degrees of belief should fit with your old ones, while Reflection is a norm enjoining you to defer to the degrees of belief that you expect to have in the future. But they are independently problematic and should be replaced by improved, time-slice-centric principles. Conditionalization should be replaced by a synchronic norm saying what degrees of belief you ought to have given your current evidence and Reflection should be replaced by a norm which instructs you to defer to the degrees of belief of agents you take to be experts. These replacement principles do all the work that the old principles were supposed to do while avoiding their problems. In this way, Time-Slice Rationality puts the theory of rationality on firmer foundations and yields better norms than alternative, non-time-slice-centric approaches. (shrink)

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)

According to epistemological disjunctivism (ED), in paradigmatic cases of perceptual knowledge, a subject, S, has perceptual knowledge that p in virtue of being in possession of reasons for her belief that p which are both factive and reflectively accessible to S. It has been argued that ED is better placed than both knowledge internalism and knowledge externalism to undercut underdetermination-based skepticism. I identify several principles that must be true if ED is to be uniquely placed to attain this goal. After (...) that, I use those principles to formulate a diachronic skeptical argument. This argument yields the counterintuitive conclusion that understanding a global skeptical hypothesis is all it takes for a rational subject to lose all her perceptual knowledge of the world. Next, I show that a popular Austinian move must reject one or another of the principles that underlie ED. I close by delineating a novel strategy that can block the diachronic skeptical argument while preserving all the principles. The key idea is that perceptual knowledge is grounded in primitive, perceptual and recognitional abilities. This view sheds new light on some puzzling features of global skepticism that have been noted by Descartes and Hume, among others. (shrink)

Some arguments include imperative clauses. For example: ‘Buy me a drink; you can’t buy me that drink unless you go to the bar; so, go to the bar!’ How should we build a logic that predicts which of these arguments are good? Because imperatives aren’t truth apt and so don’t stand in relations of truth preservation, this technical question gives rise to a foundational one: What would be the subject matter of this logic? I argue that declaratives are used to (...) produce beliefs, imperatives are used to produce intentions, and beliefs and intentions are subject to rational requirements. An argument will strike us as valid when anyone whose mental state satisfies the premises is rationally required to satisfy the conclusion. For example, the above argument reflects the principle that it is irrational not to intend what one takes to be the necessary means to one’s intended ends. I argue that all intuitively good patterns of imperative inference can be explained using off-the-shelf formulations of our rational requirements. I then develop a formal-semantic theory embodying this view that predicts a range of data, including free-choice effects and Ross’s paradox. The resulting theory shows one way that our aspirations to rational agency can be discerned in the patterns of our speech, and is a case study in how the philosophy of language and the philosophy of action can be mutually illuminating. (shrink)

Based on the dispute between Protagoras and Socrates on the origin of ethics, one can ask the question of whether the principle of ethics is reason orfeeling/emotion, or whether ethics is grounded on reason or feeling/emotion. The development of Kant’s thoughts on ethics shows the tension between reason and feeling/emotion. In Kant’s final critical ethics, he held to a principle of “rational a priori.” On the one hand, this is presented as the rational a priori (...) class='Hi'>principle being the binding principle of judgment. On the other hand, it is presented as the doctrine of “rational fact” as the ultimate argument of his ethics. Husserl believed that Kant’s doctrine of a rational a priori totally disregarded the a priori essential laws of feeling. Like Husserl, Scheler criticized Kant’s doctrine of a rational a priori, and therefore developed his own theory of an “emotional a priori”. Both of them focused their critiques on the grounding level of ethics. Scheler, however, did not follow Husserl all the way, but criticized him and reflected on his thoughts. At last, he revealed the primary status of a phenomenological material ethics of value. (shrink)

A puzzle of an unmarked clock, used by Timothy Williamson to question the KK principle, was separately adapted by David Christensen and Adam Elga to critique a principle of Rational Reflection. Both authors, we argue, flout the received relationship between ideal agency and the classical distinction between systematic and random error, namely that ideal agents are subject only to the latter. As a result, these criticisms miss their mark.

Sometimes a proposition is ‘opaque’ to an agent: he doesn't know it, but he does know something about how coming to know it should affect his or her credence function. It is tempting to assume that a rational agent's credence function coheres in a certain way with his or her knowledge of these opaque propositions, and I call this the ‘Opaque Proposition Principle’. The principle is compelling but demonstrably false. I explain this incongruity by showing that the (...) principle is ambiguous: the term ‘know’ as it appears in the principle can be interpreted in two different ways, as either basic-know or super-know. I use this distinction to construct a plausible version of the principle, and then to similarly construct plausible versions of the Reflection Principle and the Sure-Thing Principle. (shrink)

Show more ▾ There are various dichotomies in Kant’s philosophy: sensibility vs. rationality, nature vs. freedom, cognition vs. morality, noumenon vs. phenomenon, among others. There are also different ways of mediating these dichotomies, which is the systematic undertaking of Kant’s Critique of the Power of Judgment. One of the most important concepts in this work is the sublime, which exemplifies the connections between the different dichotomies; this fact means the concept’s construction is full of tension. On the one hand, as (...) a pure reflection of aesthetic judgment the sublime must be without interest or purpose, but on the other hand it is “based on the concept of reason” (KU AA:292). On the one hand, the sublime “represents merely the subjective play of the powers of the mind (imagination and reason) as harmonious” (KU AA5:258), but on the other hand, reason “exercises dominion over sensibility” and the imagination is “purposively determined in accordance with a law” of reason (KU AA5:268f). Taking into account these problems concerning the essential definition the sublime, this paper will first illustrate how the sublime embodies the a priori principle of aesthetic judgment through contrasting the judgment of the sublime with the judgment of taste in order to establish a basic logical frame for the judgment of the sublime. Second, this paper redefines the boundary between the mathematically and dynamically sublime in order to reveal both the coexistence of contemplation and movement within the sublime and the unrevealed function of reason and imagination. Finally, contrasting the sublime with moral feeling, this paper elaborates the turning-structure (from sensibility to rationality and from object-intuition to idea-exhibition) of the sublime. (shrink)

T. M. Scanlon suggests that the binding nature of promises itself plays a role in allowing a promisee rationally to expect follow through even while that binding nature itself depends on the promisee’s rational expectation of follow through. Kolodny and Wallace object that this makes the account viciously circular. The chapter defends Scanlon’s theory from this objection. It argues that the basic complaint is a form of wrong kinds of reason objection. The thought is that the promisee’s reason to (...) expect compliance are undermined if the promise is binding only when the promisee forms that very expectation. The chapter suggests that other uncontroversially rational processes of multi-person coordination involve beliefs with the very same feature. Focal point reasoning in the theory of games is one example. In coordination situations it can be rational to believe that another person will do something precisely because that person expects you to believe what one does about what they’ll do. An examination of the reasoning in such cases motivates a group reflection principle that vindicates the reasoning employed in Scanlon’s account. -/- . (shrink)

Abstract: Theories of epistemic rationality that take disagreement (or other higher-order evidence) seriously tend to be “modest” in a certain sense: they say that there are circumstances in which it is rational to doubt their correctness. Modest views have been criticized on the grounds that they undermine themselves—they’re self-defeating. The standard Self-Defeat Objections depend on principles forbidding epistemically akratic beliefs; but there are good reasons to doubt these principles—even New Rational Reflection, which was designed to allow for (...) certain special cases that are intuitively akratic. On the other hand, if we construct a Self-Defeat Objection without relying on anti-akratic principles, modest principles turn out not to undermine themselves. In the end, modesty should not be seen as a defect in a theory of rational belief. (shrink)

I want to examine the implications of a metaphysical thesis which is presupposed in various objections to Rawls' theory of justice.Although their criticisms differ in many respects, they concur in employing what I shall refer to as the continuity thesis. This consists of the following claims conjointly: (1) The parties in the original position (henceforth the OP) are, and know themselves to be, fully mature persons who will be among the members of the well-ordered society (henceforth the WOS) which is (...) generated by their choice of principles of justice. (2) The OP is a conscious event among others, integrated (compatibly with the constraints on knowledge and motivation imposed on the parties) into the regular continuity of experience that comprises each of their ongoing constitutes lives. (3) The parties in the OP thus are, and regard themselves as, psychologically continuing persons, partially determined in personality and interests by prior experiences, capable of recollection and regret concerning the past, anticipation and apprehensiveness regarding the future, and so on. Although the continuity thesis as stated above is not at odds with any of the conditions that define the OP, its exegetical validity is a matter for discussion. I shall be concerned to argue that if it is indeed contained in or a consequence of Rawls' theory, then it casts into doubt the capacity of the OP to generate or justify any principles of justice at all. On the other hand, if the continuity thesis is viewed as dispensable and unnecessary to the Rawlsian enterprise, then Rawls is correct in maintaining the irrelevance of the question of personal identity to the construction of his moral theory. In this case, the contract-theoretic, instrumentalist justification for the two principles of justice (henceforth the 2PJ) needs to be supplanted by a modified conception of wide reflective equilibrium. The considerations that form the bulk of this discussion then may be understood as providing a rationale for Rawls' recent revisions in the model of justification on which his theory of justice rests, and for his increasing emphasis on us as moral mediators between the OP and the WOS. Now I want to consider the question of whether or not, given the textual evidence, anything like the continuity thesis is stated or implied by Rawls, and what problems for his theory, if any, turn on a positive or negative answer to this question. -/- . (shrink)

LLMs have dramatically improved in capabilities in recent years. This raises the question of whether LLMs could become genuine agents with beliefs and desires. This paper demonstrates an in principle limit to LLM agency, based on their architecture. LLMs are next word predictors: given a string of text, they calculate the probability that various words can come next. LLMs produce outputs that reflect these probabilities. I show that next word predictors are exploitable. If LLMs are prompted to make probabilistic (...) predictions about the world, these predictions are guaranteed to be incoherent, and so Dutch bookable. If LLMs are prompted to make choices over actions, their preferences are guaranteed to be intransitive, and so money pumpable. In short, the problem is that selecting an action based on its potential value is structurally different then selecting the description of an action that is most likely given a prompt: probability cannot be forced into the shape of expected value. The in principle exploitability of LLMs raises doubts about how agential they can become. This exploitability also offers an opportunity for humanity to safely control such AI systems. (shrink)

This paper concentrates on a particular sort of case where it’s plausible that epistemic requirements can conflict: cases where an agent’s higher-order evidence supports doubting her reliability in reacting to her ordinary evidence. Conflicting epistemic requirements can be seen as generating epistemic dilemmas. The paper examines two ways that people have sought to recognize conflicting requirements without allowing them to generate epistemic dilemmas: separating epistemic norms into two different varieties, and positing rational indeterminacy in cases where principles conflict. It (...) argues that these views incur costs, and that the sense in which they avoid dilemmas does not gain them an advantage over a view that simply recognizes dilemmas as a natural outgrowth of agents’ rational reflection on their own thinking. (shrink)

The methods of philosophical consultation vary enormously according to the practitioners who conceive and apply them. In this paper, we discuss the conceptions and methods we have been carrying out for several years in this field, such as philosophical naturalism, the dual requirement, first steps, anagogy and discrimination, thinking the unthinkable, switching to the "second floor", and being philosophical. Our methodology is mainly inspired by the Socratic maieutic, where the philosopher questions his interlocutor, invites him to identify the stakes of (...) his discourse, to conceptualize it by distinguishing key terms in order to implement them, to problematize it through a critical perspective, to universalize its implications. This practice has the specificity of inviting the subject to move away from a mere sensation to allow him a rational analysis of his speech and of himself, a sine qua non condition for deliberating on the cognitive and existential stakes which must be made explicit at first. The removal from oneself that this unnatural activity presupposes, for which it requires the assistance of a specialist, poses a certain number of difficulties, e.g., frustration, speech as a pretext, the issue of truth, pain and epidural. Finally, some additional exercises are very useful for the reflection process, such as establishing connections, real speech, order, universal and singular, and accepting the pathology. (shrink)

“Bodily autonomy” has received significant attention in bioethics, medical ethics, and medical law in terms of the general inviolability of a patient’s bodily sovereignty and the rights of patients to make choices (e.g., reproductive choices) that concern their own body. However, the role of the body in terms of how it can or does contribute to a patient’s capacity for, or exercises of their autonomy in clinical decision-making situations has not been explicitly addressed. The approach to autonomy in this paper (...) is aligned with traditional theories that conceive autonomy in terms of an individual’s capacities for, and exercises of rational reflection. However, at the same time, this paper extends these accounts by arguing that autonomy is, in part, embodied. Specifically, by drawing on phenomenological conceptions of the experience of autonomy, we argue that, in principle, the body is a necessary component of the capacity for autonomy. Secondly, through the presentation of two different cases, we highlight ways in which a patient’s body can contribute to the autonomy of treatment choices. Ultimately, we hope to encourage others to explore additional conditions under which a concept of embodied autonomy should be employed in medical decision making, how its underlying principles might be operationalised in clinical situations, and its consequences for approaches to patient autonomy in healthcare practice, policy, and law. (shrink)

Having assigned experience this exclusive role in justification, empiricists then have a range of views concerning the character of experience, the semantics of our claims about unobservable entities, the nature of empirical confirmation, and the possibility of non-empirical warrant for some further class of claims, such as those accepted on the basis of linguistic or logical rules. Given the definitive principle of their position, empiricists can allow that we have knowledge independent of experience only where what is known is (...) not some objective fact about the world, but something about our way of conceptualizing or describing things. Some empiricists say we have knowledge of verbal equivalences or trivialities; some argue that any non-empirical tenets are not even properly called knowledge, but should be seen as notions accepted on pragmatic rather than properly epistemic grounds. What no empiricist will allow is substantive a priori knowledge: according to empiricism we have no pure rational insight into real necessities or the inner structure of nature, but must rely on the deliverances of our senses for all of our information about external reality. Some versions of empiricism argue against the very notion of real necessities or metaphysical structure behind the phenomena; other versions take a more agnostic approach, arguing that if there is a metaphysical structure behind the phenomena it is either out of our epistemic reach, or known only to the extent that it can be grasped through experience, rather than through rational reflection. (shrink)

Many have claimed that whenever an investigation might provide evidence for a claim, it might also provide evidence against it. Similarly, many have claimed that your credence should never be on the edge of the range of credences that you think might be rational. Surprisingly, both of these principles imply that you cannot rationally be modest: you cannot be uncertain what the rational opinions are.

The Sleeping Beauty problem has attracted considerable attention in the literature as a paradigmatic example of how self-locating uncertainty creates problems for the Bayesian principles of Conditionalization and Reflection. Furthermore, it is also thought to raise serious issues for diachronic Dutch Book arguments. I show that, contrary to what is commonly accepted, it is possible to represent the Sleeping Beauty problem within a standard Bayesian framework. Once the problem is correctly represented, the ‘thirder’ solution satisfies standard rationality principles, vindicating (...) why it is not vulnerable to diachronic Dutch Book arguments. Moreover, the diachronic Dutch Books against the ‘halfer’ solutions fail to undermine the standard arguments for Conditionalization. The main upshot that emerges from my discussion is that the disagreement between different solutions does not challenge the applicability of Bayesian reasoning to centered settings, nor the commitment to Conditionalization, but is instead an instance of the familiar problem of choosing the priors. (shrink)

This paper examines the following three questions: (1) In The Rose Garden of Mystery (Golshan-e Rāz), how does the prominent 7-8th-century Iranian Sufi, Maḥmūd Shabistarī, distinguish the mystical “contemplation” and “rational reflection” in pursuing divine knowledge? (2) Was Shabistarī an anti-rationalist (strict fideist)? (3) How does Shabistarī’s position fit into the ancient Greek, Neoplatonist, and medieval Islamic and Christian metaphysics? This paper examines Golshan-e Rāz in the context of Shabistarī’s other works, commentaries, secondary sources, and Islamic thought—Sufism and (...) philosophy. Existing literature on Golshan-e Rāz primarily focuses on its literary aspects, neglecting its philosophical and mystical concepts. However, a thorough understanding requires examining these concepts in a broad context, which will inspire further research. The rationale behind this research is rooted in the religious obligation for believers to know God, with “thinking” as the means to acquire such knowledge. This is why the first question Herawī poses to Shabistarī pertains to the nature of thought—justifying this paper’s focus. Contemporary opposition to religion often stems from its perceived incongruity with the rational frameworks offered by positivism, materialism, or scientific inquiry. By differentiating between mystical and rational modes of thought that Shabistarī presents, this study shows the contemporary person that intellectual inquiry extends beyond rationalism and encompasses mysticism. Consequently, rational and mystical perspectives should be pursued in the quest for the divine. Furthermore, this study contends that Shabistarī should not be regarded as a strict fideist; instead, his criticism is directed toward the constraints inherent in rational thinking. (shrink)

I develop and defend the view that subjects are necessarily psychologically able to revise their beliefs in response to relevant counter-evidence. Specifically, subjects can revise their beliefs in response to relevant counter-evidence, given their current psychological mechanisms and skills. If a subject lacks this ability, then the mental state in question is not a belief, though it may be some other kind of cognitive attitude, such as a supposition, an entertained thought, or a pretense. The result is a moderately revisionary (...) view of belief: while most mental states we thought were beliefs are beliefs, some mental states which we thought were beliefs are not beliefs. The argument for this view draws on two key claims: First, subjects are rationally obligated to revise their beliefs in response to relevant counter-evidence. Second, if some subject is rationally obligated to revise one of her mental states, then that subject can revise that mental state, given her current psychological mechanisms and skills. Along the way to defending these claims, I argue that rational obligations can govern activities which reflect on one’s rational character, whether or not those activities are under one’s voluntary control. I also show how the relevant version of epistemic ‘ought’ implies ‘can’ survives an objection which plagues other variants of the principle. (shrink)

There appears to be a tension between two commitments in liberalism. The first is that citizens, as rational agents possessing dignity, are owed a justification for principles of justice. The second is that members of society who do not meet the requirements of rational agency are owed justice. These notions conflict because the first commitment is often expressed through the device of the social contract, which seems to confine the scope of justice to rational agents. So, contractarianism (...) seems to ignore the justice claims of the severely cognitively impaired. To solve this problem, Martha Nussbaum proposes the capabilities approach. The justifiability condition, on this approach, is met by the idea of overlapping consensus. This essay argues that overlapping consensus cannot meet liberalism’s justifiability condition, nor is it more inclusive of the cognitively impaired. Therefore, we have reason to retain the contract device and look for another way to ensure that liberalism respects the justice claims of all. (shrink)

Two principles in epistemology are apparent examples of the close connection between rationality and truth. First, adding a disjunct to what it is rational to believe yields a proposition that’s also rational to believe. Second, what’s likely if believed is rational to believe. While these principles are accepted by many, it turns out that they clash. In light of this clash, we must relinquish the second principle. Reflecting on its rationale, though, reveals that there are two (...) distinct ways to understand the connection between rationality and truth. Rationality is fundamentally a guide to the belief-independent truth, rather than a guide to acquiring true beliefs. And this in turn has important implications for current discussions of permissivism, epistemic reasons, and epistemic consequentialism. (shrink)

The probabilities a Bayesian agent assigns to a set of events typically change with time, for instance when the agent updates them in the light of new data. In this paper we address the question of how an agent's probabilities at different times are constrained by Dutch-book coherence. We review and attempt to clarify the argument that, although an agent is not forced by coherence to use the usual Bayesian conditioning rule to update his probabilities, coherence does require the agent's (...) probabilities to satisfy van Fraassen's [1984] reflection principle (which entails a related constraint pointed out by Goldstein [1983]). We then exhibit the specialized assumption needed to recover Bayesian conditioning from an analogous reflection-style consideration. Bringing the argument to the context of quantum measurement theory, we show that "quantum decoherence" can be understood in purely personalist terms---quantum decoherence (as supposed in a von Neumann chain) is not a physical process at all, but an application of the reflection principle. From this point of view, the decoherence theory of Zeh, Zurek, and others as a story of quantum measurement has the plot turned exactly backward. (shrink)

I present an argument against the thesis of Uniqueness and in favour of Permissivism. Counterexamples to Uniqueness are provided, based on ‘Safespot’ propositions – i.e. a proposition that is guaranteed to be true provided the subject adopts a certain attitude towards it. The argument relies on a plausible principle: (roughly stated) If S knows that her believing p would be a true belief, then it is rationally permitted for S to believe p. One motivation for denying this principle (...) – viz. opposition to ‘epistemic consequentialism’ – is briefly discussed. The principle is extended to cover degrees of belief and compared with a couple of other well-known constraints on rational degrees of belief. (shrink)

We introduce and consider the inner-model reflection principle, which asserts that whenever a statement \varphi(a) in the first-order language of set theory is true in the set-theoretic universe V, then it is also true in a proper inner model W \subset A. A stronger principle, the ground-model reflection principle, asserts that any such \varphi(a) true in V is also true in some non-trivial ground model of the universe with respect to set forcing. These principles each (...) express a form of width reflection in contrast to the usual height reflection of the Lévy–Montague reflection theorem. They are each equiconsistent with ZFC and indeed \Pi_2-conservative over ZFC, being forceable by class forcing while preserving any desired rank-initial segment of the universe. Furthermore, the inner-model reflection principle is a consequence of the existence of sufficient large cardinals, and lightface formulations of the reflection principles follow from the maximality principle MP and from the inner-model hypothesis IMH. We also consider some questions concerning the expressibility of the principles. (shrink)

We investigate the theory IΔ 0 + Ω 1 and strengthen [Bu86. Theorem 8.6] to the following: if NP ≠ co-NP. then Σ-completeness for witness comparison formulas is not provable in bounded arithmetic. i.e. $I\delta_0 + \Omega_1 + \nvdash \forall b \forall c (\exists a(\operatorname{Prf}(a.c) \wedge \forall = \leq a \neg \operatorname{Prf} (z.b))\\ \rightarrow \operatorname{Prov} (\ulcorner \exists a(\operatorname{Prf}(a. \bar{c}) \wedge \forall z \leq a \neg \operatorname{Prf}(z.\bar{b})) \urcorner)).$ Next we study a "small reflection principle" in bounded arithmetic. We prove (...) that for all sentences φ $I\Delta_0 + \Omega_1 \vdash \forall x \operatorname{Prov}(\ulcorner \forall y \leq \bar{x} (\operatorname{Prf} (y. \overline{\ulcorner \varphi \urcorner}) \rightarrow \varphi)\urcorner).$ The proof hinges on the use of definable cuts and partial satisfaction predicates akin to those introduced by Pudlak in [Pu86]. Finally, we give some applications of the small reflection principle, showing that the principle can sometimes be invoked in order to circumvent the use of provable Σ-completeness for witness comparison formulas. (shrink)

It is a consequence of the theory of imprecise credences that there exist situations in which rational agents inevitably become less opinionated toward some propositions as they gather more evidence. The fact that an agent's imprecise credal state can dilate in this way is often treated as a strike against the imprecise approach to inductive inference. Here, we show that dilation is not a mere artifact of this approach by demonstrating that opinion loss is countenanced as rational by (...) a substantially broader class of normative theories than has been previously recognised. Specifically, we show that dilation-like phenomena arise even when one abandons the basic assumption that agents have (precise or imprecise) credences of any kind, and follows directly from bedrock norms for rational comparative confidence judgements of the form `I am at least as confident in p as I am in q'. We then use the comparative confidence framework to develop a novel understanding of what exactly gives rise to dilation-like phenomena. By considering opinion loss in this more general setting, we are able to provide a novel assessment of the prospects for an account of inductive inference that is not saddled with the inevitability of rational opinion loss. (shrink)

This essay develops the epistemic challenge to non-naturalist moral realism. While evolutionary considerations do not support the strongest claims made by ‘debunkers’, they do provide the basis for an inductive argument that our moral dispositions and starting beliefs are at best partially reliable. So, we need some method for separating truth from falsity. Many non-naturalists think that rational reflection can play this role. But rational reflection cannot be expected to bring us to truth even from reasonably (...) accurate starting points. Reflection selects views that are coherent and conflict-free, yet there is no reason to think that the non-natural moral truth must be like this. Inasmuch as we seek coherent, conflict-free, ethical viewpoints, that suggests that our goal is not non-natural truth at all. (shrink)

This chapter discusses the fundamental question of the defense industry’s role and legitimacy for societies. It begins with a parable of a psychopath doing something self-serving that has beneficial moral consequences. Analogously, it is argued, the defense industry profiting by selling weapons that can kill people makes it useful in solving moral problems not solvable by people with ordinary moral scruples. Next, the chapter argues that while the defense industry is a business, it is also implicated in the security of (...) its home nations. In addition, its products can be used for good or evil. Thus, it must navigate conflicting values, with the result that the rules often thought to rightly regulate the industry—codes of business ethics, engineering ethics, procurement ethics, plus laws of the land, and dicta of conscience—need supplementing by general moral reflection. This chapter argues for a principle that tells how to decide when to violate the rules, for a theory of rational choice on which choosing by this principle is rational, and for teaching that theory to defense industry employees to ensure their ethical behavior. (shrink)

This paper is about the alethic aspect of epistemic rationality. The most common approaches to this aspect are either normative (what a reasoner ought to/may believe?) or evaluative (how rational is a reasoner?), where the evaluative approaches are usually comparative (one reasoner is assessed compared to another). These approaches often present problems with blindspots. For example, ought a reasoner to believe a currently true blindspot? Is she permitted to? Consequently, these approaches often fail in describing a situation of alethic (...) maximality, where a reasoner fulfills all the alethic norms and could be used as a standard of rationality (as they are, in fact, used in some of these approaches). I propose a function α, which accepts a set of beliefs as inputand returns a numeric alethic value. Then I use this function to define a notion of alethic maximality that is satisfiable by finite reasoners (reasoners with cognitive limitations) and does not present problems with blindspots. Function α may also be used in alethic norms and evaluation methods (comparative and non-comparative) that may be applied to finite reasoners and do not present problems with blindspots. A result of this investigation isthat the project of providing purely alethic norms is defective. The use of function α also sheds light on important epistemological issues, such as the lottery and the preface paradoxes, and the principles of clutter avoidance and reflection. (shrink)

Modern philosophy recognizes two major ethical theories: deontology, which encourages adherence to rules and fulfillment of duties or obligations; and consequentialism, which evaluates morally significant actions strictly on the basis of their actual or anticipated outcomes. Both involve the systematic application of universal abstract principles, reflecting the culturally dominant paradigm of technical rationality. Professional societies promulgate codes of ethics with which engineers are expected to comply, while courts and the public generally assign liability to engineers primarily in accordance with the (...) results of their work, whether intended or unintended. A third option, prominent in ancient philosophy, has reemerged recently: virtue ethics, which recognizes that sensitivity to context and practical judgment are indispensable in particular concrete situations, and therefore rightly focuses on the person who acts, rather than the action itself. Beneficial character traits—i.e., virtues—are identified within a specific social practice in light of the internal goods that are unique to it. This paper proposes a comprehensive framework for implementing virtue ethics within engineering. (shrink)

L.A. Paul has argued that an ordinary, natural way of making a decision -- by reflecting on the phenomenal character of the experiences one will have as a result of that decision -- cannot yield rational decision in certain cases. Paul's argument turns on the (in principle) epistemically inaccessible phenomenal character of certain experiences. In this paper I argue that, even granting Paul a range of assumptions, her argument doesn't work to establish its conclusion. This is because, as (...) I argue, the phenomenal character of an experience supervenes on epistemically accessible facts about its non-phenomenal character plus what the deciding agent is like. Because there are principles that link the non-phenomenal character of experiences (together with what a particular agent is like) to the phenomenal character of experiences, agents can reasonably form expectations about the valence of the phenomenal character of the experiences that they are deciding whether to undergo. These reasonable expectations are, I argue, enough to make the ordinary, natural way of making a decision yield rational decision. (shrink)

This thesis sets out an argument in defence of moral objectivism. It takes Mackie as the critic of objectivism and it ends by proposing that the best defence of objectivism may be found in what I shall call Kantian intuitionism, which brings together elements of the intuitionism of Ross and a Kantian epistemology. The argument is fundamentally transcendental in form and it proceeds by first setting out what we intuitively believe, rejecting the sceptical attacks on those beliefs, and by then (...) proposing a theory that can legitimize what we already do believe. Chapter One sets out our intuitive understanding of morality: that morality is cognitive, moral beliefs can be true or false; that morality is real, we do not construct it; that morality is rational, we can learn about it by rational investigation; and that morality places us under an absolute constraint. The chapter ends by clarifying the nature of that absolute demand and by arguing that the critical idea within morality is the idea of duty. In Chapter Two Mackie’s sceptical attack on objectivism is examined. Four key arguments are identified: that moral beliefs are relative to bfferent agents; that morality is based upon on non-rational causes; that the idea of moral properties or entities is too queer to be sustainable; and that moral objectivism involves queer epistemological commitments. Essentially all of these arguments are shown to be ambiguous; however it is proposed that Mackie has an underlying epistemological and metaphysical theory, scientific empiricism, which is hostile to objectivism and a theory that many find attractive for reasons that are independent of morality. Chapter Three explores the nature of moral rationality and whether scientific empiricism can use the idea of reflective equilibrium to offer a reasonable account of moral rationality. It concludes that, while reflective equilibrium is a useful account of moral rationality, it cannot be effectively reconciled with scientific empiricism. In order to function effectively as a rational process, reflective equilibrium must be rationally constrained by our moral judgements and our moral principles. Chapter Four begins the process of exploring some alternative epistemologies and argues that the only account that remains true to objectivism and the needs of reflective equilibrium is the account of intuitionism proposed by Ross. However this account can be developed further by drawing upon number of Kantian ideas and using them to supplement Ross’s intuitionism. So Chapter Five draws upon a number of Kant's ideas, most notably some key notions from the Critique of Judgement. These ideas are: that we possess a rational will that is subject to the Moral law and determined by practical reason; that we possess a faculty of judgement which enables us to become aware of moral properties and that these two faculties together with the third faculty of thought can function to constitute the moral understanding. Using these ideas the thesis explores whether they can serve to explain how intuitions can be rational and how objectivism can be justified. (shrink)

The paper discusses Husserl’s method of historical reflection, radical Besinnung, as defined and used in Formale und transzendentale Logik (1929). Whereas Formal and Transcendental Logic introduces and displays Husserl’s usage of Besinnung in the context of the exact sciences, the paper seeks to develop it as a more general critical method with which to approach any rational goal-directed activity. Husserl defines Besinnung as a method that enables understanding agents and their actions by explicating agents’ typically implicit goals. It (...) leads to the inclusion of historical-teleological activities as part of Husserl’s natural understanding of the world. The transcendental reflection radicalizes Besinnung by clarifying the kinds of evidence sought for in activities and then suggesting revisions to the concepts and principles used. The result is inner critique, which means that the activities are criticized against the norms that arise from reflection on these activities themselves, and not from a comparison with external standards or measures. (shrink)

The monograph is an English, expanded and revised version of the book Cheshko, V. T., Ivanitskaya, L.V., & Glazko, V.I. (2018). Anthropocene. Philosophy of Biotechnology. Moscow, Course. The manuscript was completed by me on November 15, 2019. It is a study devoted to the development of the concept of a stable evolutionary human strategy as a unique phenomenon of global evolution. The name “An Evolutionary Metaphysics (Cheshko, 2012; Glazko et al., 2016). With equal rights, this study could be entitled “Biotechnology (...) as a result and factor of the evolutionary processˮ. The choice in favor of used “The Evolutionary Metaphysics of Human Enhancement Technologiesˮ was made in accordance with the basic principle of modern post-academician and human-sized science, a classic example of which is biotechnology. The “Metaphysics of Evolution” and “Evolutionary Metaphysics” concepts are used in several ways in modern philosophical discourse. In any case, the values contain a logical or associative reference to the teleological nature of the evolutionary process (Hull, 1967, 1989; Apel, 1995; Faye, 2016; Dupre, 2017; Rose, 2018, etc). In our study, the “evolutionary metaphysics” serves to denote the thesis of the rationalization and technologization of global evolution and anthropogenesis, in particular. At the same time, the postulate of an open future remains relevant in relation to the results of the evolutionary process. The theory of evolution of complex, including the humans system and algorithm for its constructing are а synthesis of evolutionary epistemology, philosophical anthropology and concrete scientific empirical basis in modern science. ln other words, natural philosophy is regaining the status bar element theoretical science in the era of technology-driven evolution. The co-evolutionary concept of 3-modal stable evolutionary strategy of Homo sapiens is developed. The concept based оn the principle of evolutionary complementarity of anthropogenesis: value of evolutionary risk and evolutionary path of human evolution are defined bу descriptive (evolutionary efficiency) and creative-teleological (evolutionary correctness) parameters simultaneously, that cannot bе instrumental reduced to others ones. Resulting volume of both parameters define the vectors of blological, social, cultural and techno-rationalistic human evolution Ьу two gear mechanism genetic and cultural co-evolution and techno-humanitarian balance. The resultant each of them сап estimated Ьу the ratio of socio-psychological predispositions of humanization / dehumanization in mentality. Explanatory model and methodology of evaluation of creatively teleological evolutionary risk component of NBIC technological complex is proposed. Integral part of the model is evolutionary semantics (time-varying semantic code, the compliance of the blological, socio-cultural and techno-rationalist adaptive modules of human stable evolutionary strategy). It is seem necessary to make three clarifications. First, logical construct, “evolutionary metaphysics” contains an internal contradiction, because it unites two alternative explanatory models. “Metaphysics”, as a subject, implies deducibility of the process from the initial general abstract principle, and, consequently, the outcome of the development of the object is uniquely determined by the initial conditions. Predicate, “evolutionary”, means stochastic mechanism of realizing the same principle by memorizing and replicating random choices in all variants of the post-Darwin paradigm. In philosophy, random choice corresponds to the category of “free will” of a reasonable agent. In evolutionary theory, the same phenomenon is reflected in the concept of “covariant replication”. Authors will attempt to synthesize both of these models in a single transdisciplinary theoretical framework. Secondly, the interpretation of the term “evolutionary (adaptive) strategyˮ is different from the classical definition. The difference is that the adaptive strategy in this context is equivalent to the survival, i.e. it includes the adaptation to the environment and the transformation (construction) of the medium in accordance with the objectives of survival. To emphasize this difference authors used verbal construction “adaptiveˮ (rather than “evolutionaryˮ) strategy as more adequate. In all other cases, the two terms may be regarded as synonymous. Thirdly, the initial two essays of this series were published in one book in 2012. Their main goal was the development of the logically consistent methodological concept of stable adaptive (evolutionary) strategy of hominines and the argumentation of its heuristic possibilities as a transdisciplinary scientific paradigm of modern anthropology. The task was to demonstrate the possibilities of the SESH concept in describing and explaining the evolutionary prospects for the interaction of social organization and technology (techno-humanitarian balance) and the associated biological and cultural mechanisms of the genesis of religion (gene-cultural co-evolution). In other words, it was related to the sphere of cultural and philosophical anthropology, i.e. to the axiological component of any theoretical constructions describing the behavior of self-organizing systems with human participation. In contrast, the present work is an attempt to introduce this concept into the sphere of biological anthropology and, consequently, its main goal is to demonstrate the possibility of verification of its main provisions by means of procedures developed by natural science, i.e. refers to the descriptive component of the same theoretical constructions. The result of this in the future should be methods for assessing, calculating and predicting the risk of loss of biological and cultural identity of a person, associated with a permanent and continuously deepening process of development of science and technology. (shrink)

“Probably Peirce’s best-known works are the first two articles in a series of six that originally were collectively entitled Illustrations of the Logic of Science and published in Popular Science Monthly from November 1877 through August 1878. The first is entitled ‘The Fixation of Belief’ and the second is entitled ‘How to Make Our Ideas Clear.’ In the first of these papers Peirce defended, in a manner consistent with not accepting naive realism, the superiority of the scientific method over other (...) methods of overcoming doubt and ‘fixing belief.’” — Robert Burch, “Charles Sanders Peirce,” entry in the Stanford Encyclopedia of Philosophy (2021 revision) -/- “Pragmatist epistemologies often explore how we can carry out inquiries in a self-controlled and fruitful way. (Where much analytic epistemology centres around the concept of knowledge, considered as an idealised end-point of human thought, pragmatist epistemology centres around the concept of inquiry, considered as the process of knowledge-seeking and how we can improve it.) So pragmatists often provide rich accounts of the capacities or virtues that we must possess in order to inquire well, and the rules or guiding principles that we should adopt. A canonical account is Peirce’s classic early paper ‘The Fixation of Belief‘. Here Peirce states that inquiry is a struggle to replace doubt with “settled belief“, and that the only method of inquiry that can make sense of the fact that at least some of us are disturbed by inconsistent beliefs, and will subsequently reflect upon which methods of fixing belief are correct is the Method of Science, which draws on the Pragmatic Maxim described above. This contrasts with three other methods of fixing belief: i) refusing to consider evidence contrary to one’s favored beliefs (the Method of Tenacity), ii) accepting an institution’s dictates (the Method of Authority), iii) developing the most rationally coherent or elegant-seeming belief-set (the A Priori Method).“ — Catherine Legg, “Pragmatism,” entry in the Stanford Encyclopedia of Philosophy (2021 revision). (shrink)

Certain situations seem to call for acknowledging the possibility that one’s own beliefs are biased or distorted. On the other hand, certain sorts of epistemic self-doubts (such as ‘I believe it’s raining, but it’s not’) seem paradoxical. And some have put forth epistemic principles requiring rational agents to regard their own credences as so-called ‘expert functions’. This paper examines the question of whether rationality requires agents to respect their own credences in a way in which they need not respect (...) the credences of others. (shrink)

Early moderns such as Locke and Descartes thought we could guarantee the justification of our beliefs, even in worlds most hostile to their truth, if only we form those beliefs with sufficient care. That is, they thought it possible for us to be impeccable with respect to justification. This principle has traditionally been used to argue for internalism. By placing all of the normatively relevant conditions in our minds, we ensure reflective access to what those norms require of us (...) and so sustain the possibility of impeccability (unlike externalism). However, recent challenges to transparency leave this reasoning vulnerable. In response, I show how impeccability can be sustained without requiring transparency. The account only works if we define internal states as those directly accessible to our rational belief forming systems. I argue that this sort of causal internalism, while somewhat revisionary, preserves traditional motivations for internalism while avoiding problems faced by other varieties. The result is a renewed argument for internalism that simultaneously moves us away from access internalism and towards a species of mentalism. (shrink)

You omega know something when you know it, and know that you know it, and know that you know that you know it, and so on. This paper first argues that omega knowledge matters, in the sense that it is required for rational assertion, action, inquiry, and belief. The paper argues that existing accounts of omega knowledge face major challenges. One account is skeptical, claiming that we have no omega knowledge of any ordinary claims about the world. Another account (...) embraces the KK thesis, and identifies knowledge with omega knowledge. This position faces counterexamples, and struggles to make sense of inexact knowledge. The paper then develops a new account of knowledge, by proposing the principle of Reflective Luminosity: if you know that you know something, then you omega know it. I argue that Reflective Luminosity allows for omega knowledge while avoiding the problems for KK. (shrink)

Whatever may be said about contemporary feminists’ evaluation of Descartes’ role in the history of feminism, Mary Astell herself believed that Descartes’ philosophy held tremendous promise for women. His urging all people to eschew the tyranny of custom and authority in order to uncover the knowledge that could be found in each one of our unsexed souls potentially offered women a great deal of intellectual and personal freedom and power. Certainly Astell often read Descartes in this way, and Astell herself (...) has been interpreted as a feminist – indeed, as the first English feminist. But a close look at Astell’s and Descartes’ theories of reason, and the role of authority in knowledge formation as well as in their philosophies of education, show that there are subtle yet crucial divergences in their thought – divergences which force us to temper our evaluation of Astell as a feminist. -/- My first task is to evaluate Astell’s views on custom and authority in knowledge formation and education by comparing her ideas with those of Descartes. While it is true that Astell seems to share Descartes’ wariness of custom and authority, a careful reading of her work shows that the wariness extends only as far as the tyranny of custom over individual intellectual development. It does not extend to a wariness about social and institutional customs and authority (including, perhaps most crucially, the institution of marriage as we see in her Reflection on Marriage). The reason for this is that Astell’s driving goal is to help women to come to know God’s plan for women – both in their roles as human and in their roles as women. According to Astell, while it is true that, as individuals, women must develop their rational capacities to the fullest in order to honor God and his plan for women as human, as members of social institutions, including the institution of marriage, women must subordinate themselves to men, including their husbands, in this case so as to honor God and his plan for women as women. Once we understand the theological underpinnings of her equivocal reaction to authority and custom, we can see that Astell may be considered a feminist in a very tempered way. -/- My second task is to use these initial conclusions to re-read her proposal for single-sexed education that we find in A Serious Proposal to the Ladies. It is true that Astell encourages women to join single-sexed educational institutions for the unique and empowering friendships that women can develop in such institutions. Still, my argument continues, the development of such friendships is not entirely an end in itself. Rather, Astell encourages women to develop such friendships such that they can re-enter the broader world armed with the tools that will help them endure burdensome features of the lives that await them in the world, including their lives as subordinated wives –burdens that Astell does not, in principle, challenge. (shrink)

I argue that we are sometimes morally responsible for having and using (or not using) our concepts, despite the fact that we generally do not choose to have them or have full or direct voluntary control over how we use them. I do so by extending an argument of Angela Smith's; the same features that she says make us morally responsible for some of our attitudes also make us morally responsible for some of our concepts. Specifically, like attitudes, concepts can (...) be (a) conceptually and rationally connected to our evaluative judgments, (b) in principle subject to rational revision (reasons‐responsive), and (c) the basis for actual and potential moral assessments of people that we have good reasons to endorse. Thus, we are open to moral appraisal on the basis of having and using (or not using) our concepts when they reflect our evaluative judgments, though even then it is not always appropriate to praise or blame us on that basis. (shrink)

The basic axioms or formal conditions of decision theory, especially the ordering condition put on preferences and the axioms underlying the expected utility formula, are subject to a number of counter-examples, some of which can be endowed with normative value and thus fall within the ambit of a philosophical reflection on practical rationality. Against such counter-examples, a defensive strategy has been developed which consists in redescribing the outcomes of the available options in such a way that the threatened axioms (...) or conditions continue to hold. We examine how this strategy performs in three major cases: Sen's counterexamples to the binariness property of preferences, the Allais paradox of EU theory under risk, and the Ellsberg paradox of EU theory under uncertainty. We find that the strategy typically proves to be lacking in several major respects, suffering from logical triviality, incompleteness, and theoretical insularity. To give the strategy more structure, philosophers have developed “principles of individuation”; but we observe that these do not address the aforementioned defects. Instead, we propose the method of checking whether the strategy can overcome its typical defects once it is given a proper theoretical expansion. We find that the strategy passes the test imperfectly in Sen's case and not at all in Allais's. In Ellsberg's case, however, it comes close to meeting our requirement. But even the analysis of this more promising application suggests that the strategy ought to address the decision problem as a whole, rather than just the outcomes, and that it should extend its revision process to the very statements it is meant to protect. Thus, by and large, the same cautionary tale against redescription practices runs through the analysis of all three cases. A more general lesson, simply put, is that there is no easy way out from the paradoxes of decision theory. (shrink)

Many scholars point to the close association between early modern science and the rise of rational arguments in favour of the existence of witches. For some commentators, it is a poor reflection on science that its methods so easily lent themselves to the unjust persecution of innocent men and women. In this paper, I examine a debate about witches between a woman philosopher, Margaret Cavendish , and a fellow of the Royal Society, Joseph Glanvill . I argue that (...) Cavendish is the voice of reason in this exchange—not because she supports the modern-day view that witches do not exist, but because she shows that Glanvill’s arguments about witches betray his own scientific principles. Cavendish’s responses to Glanvill suggest that, when applied consistently, the principles of early modern science could in fact promote a healthy scepticism toward the existence of witches. (shrink)

ABSTRACT. May scientists rely on substantive, a priori presuppositions? Quinean naturalists say "no," but Michael Friedman and others claim that such a view cannot be squared with the actual history of science. To make his case, Friedman offers Newton's universal law of gravitation and Einstein's theory of relativity as examples of admired theories that both employ presuppositions (usually of a mathematical nature), presuppositions that do not face empirical evidence directly. In fact, Friedman claims that the use of such presuppositions is (...) a hallmark of "science as we know it." But what should we say about the special sciences, which typically do not rely on the abstruse formalisms one finds in the exact sciences? I identify a type of a priori presupposition that plays an especially striking role in the development of empirical psychology. These are ontological presuppositions about the type of object a given science purports to study. I show how such presuppositions can be both a priori and rational by investigating their role in an early flap over psychology's contested status as a natural science. The flap focused on one of the field's earliest textbooks, William James's Principles of Psychology. The work was attacked precisely for its reliance on a priori presuppositions about what James had called the "mental state," psychology's (alleged) proper object. I argue that the specific presuppositions James packed into his definition of the "mental state" were not directly responsible to empirical evidence, and so in that sense were a priori; but the presuppositions were rational in that they were crafted to help overcome philosophical objections (championed by neo-Hegelians) to the very idea that there can be a genuine science of mind. Thus, my case study gives an example of substantive, a priori presuppositions being put to use—to rational use—in the special sciences. In addition to evaluating James's use of presuppositions, my paper also offers historical reflections on two different strands of pragmatist philosophy of science. One strand, tracing back through Quine to C. S. Peirce, is more naturalistic, eschewing the use of a priori elements in science. The other strand, tracing back through Kuhn and C. I. Lewis to James, is more friendly to such presuppositions, and to that extent bears affinity with the positivist tradition Friedman occupies. (shrink)