Perceptual Confidence is the view that perceptual experiences assign degrees of confidence. After introducing, clarifying, and motivating Perceptual Confidence, I catalogue some of its more interesting consequences, such as the way it blurs the distinction between veridical and illusory experiences, a distinction that is sometimes said to carry a lot of metaphysical weight. I also explain how Perceptual Confidence fills a hole in our best scientific theories of perception and why it implies that experiences don't have objective accuracy conditions.

Perceptual Confidence is the view that our conscious perceptual experiences assign confidence. In previous papers, I motivated it using first-personal evidence (Morrison, 2016), and Jessie Munton motivated it using normative evidence (Munton, 2016). In this paper, I will consider the extent to which it is motivated by third-personal evidence. I will argue that the current evidence is supportive but not decisive. I will then describe experiments that might provide stronger evidence. I hope to thereby provide a roadmap for future research.

I use an old challenge to motivate a new view. The old challenge is due to variation in our perceptions of secondary qualities. The challenge is to say whose perceptions are accurate. The new view is about how we manage to perceive secondary qualities, and thus manage to perceive them accurately or inaccurately. I call it perceptual structuralism. I first introduce the challenge and point out drawbacks with traditional responses. I spend the rest of the paper motivating and defending a (...) structuralist response. While I focus on color, both the challenge and the view generalize to the other secondary qualities. (shrink)

In “Perceptual Confidence,” I argue that our perceptual experiences assign degrees of confidence. In “Precision, not Confidence, Describes the Uncertainty of Perceptual Experience,” Rachel Denison disagrees. In this reply I first clarify what i mean by ‘perceptual experiences’, ‘assign’ and ‘confidence’. I then argue, contra Denison, that perception involves automatic categorization, and that there is an intrinsic difference between a blurry perception of a sharp image and a sharp perception of a blurry image. -/- .

We propose that doping be legalized under medical supervision. First, we discuss two motivations for allowing medically supervised doping. We reject the ‘compromised choice/harm minimization’ motivation as unlikely to win the support of athletes. We agree that it could lead to an arms race. Instead, we favor full acceptance of doping under medical supervision and answer Reid’s spirit of sport objection to medical manipulation. After presenting a set of guiding principles, we use them to answer the arms race objection and (...) rebut one of the most prominent objections in the literature about the safety of medically supervised doping, the game-theoretic objection. (shrink)

Enhanced indispensability arguments claim that Scientific Realists are committed to the existence of mathematical entities due to their reliance on Inference to the best explanation. Our central question concerns this purported parity of reasoning: do people who defend the EIA make an appropriate use of the resources of Scientific Realism to achieve platonism? We argue that just because a variety of different inferential strategies can be employed by Scientific Realists does not mean that ontological conclusions concerning which things we should (...) be Scientific Realists about are arrived at by any inferential route which eschews causes, and nor is there any direct pressure for Scientific Realists to change their inferential methods. We suggest that in order to maintain inferential parity with Scientific Realism, proponents of EIA need to give details about how and in what way the presence of mathematical entities directly contribute to explanations. (shrink)

The indispensability argument is a method for showing that abstract mathematical objects exist. Various versions of this argument have been proposed. Lately, commentators seem to have agreed that a holistic indispensability argument will not work, and that an explanatory indispensability argument is the best candidate. In this paper I argue that the dominant reasons for rejecting the holistic indispensability argument are mistaken. This is largely due to an overestimation of the consequences that follow from evidential holism. Nevertheless, the holistic indispensability (...) argument should be rejected, but for a different reason —in order that an indispensability argument relying on holism can work, it must invoke an unmotivated version of evidential holism. Such an argument will be unsound. Correcting the argument with a proper construal of evidential holism means that it can no longer deliver mathematical Platonism as a conclusion: such an argument for Platonism will be invalid. I then show how the reasons for rejecting the holistic indispensability argument importantly constrain what kind of account of explanation will be permissible in explanatory versions. (shrink)

Aquinas, Ockham, and Burdan all claim that a person can be numerically identical over time, despite changes in size, shape, and color. How can we reconcile this with the Indiscernibility of Identicals, the principle that numerical identity implies indiscernibility across time? Almost all contemporary metaphysicians regard the Indiscernibility of Identicals as axiomatic. But I will argue that Aquinas, Ockham, and Burdan would reject it, perhaps in favor of a principle restricted to indiscernibility at a time.

According to anti-atomism, we represent color properties (e.g., red) in virtue of representing color relations (e.g., redder than). I motivate anti-atomism with a puzzle involving a series of pairwise indistinguishable chips. I then develop two versions of anti-atomism.

This paper is an examination of evidential holism, a prominent position in epistemology and the philosophy of science which claims that experiments only ever confirm or refute entire theories. The position is historically associated with W.V. Quine, and it is at once both popular and notorious, as well as being largely under-described. But even though there’s no univocal statement of what holism is or what it does, philosophers have nevertheless made substantial assumptions about its content and its truth. Moreover they (...) have drawn controversial and important conclusions from these assumptions. In this paper I distinguish three types of evidential holism and argue that the most oft-cited and controversial thesis is entirely unmotivated. The other two theses are much overlooked, but are well-motivated and free from controversial implications. (shrink)

Spinoza’s claims about true ideas are central to the Treatise on the Emendation of the Intellect. It is therefore worth trying to reconstruct what he means when he says that an idea is true. I argue that the three leading interpretations – correspondence, coherence, and causal – don’t explain key passages. I then propose a new interpretation. Roughly, I propose that an idea is true if and only if it represents an essence and was derived in the right kind of (...) way by the intellect from an innate idea of one’s own essence. In the final section I sketch why I believe this interpretation extends to his claims about truth and adequacy in the Ethics. (shrink)

Spinoza claims that a person’s mind and body are one and the same. But he also claims that minds think and do not move, whereas bodies move and do not think. How can we reconcile these claims? I believe that Spinoza is building on a traditional view about identity over time. According to this view, identity over time is linked to essence, so that a thing that is now resting is identical to a thing that was previously moving, provided that (...) they share the same essence. I believe that Spinoza has a similar view about the identity of minds and bodies. In particular, a thing that is thinking in the attribute of thought is identical to a thing that is moving in the attribute of extension, provided that they share the same essence. (shrink)

Spinoza's causal axiom is at the foundation of the Ethics. I motivate, develop and defend a new interpretation that I call the ‘causally restricted interpretation’. This interpretation solves several longstanding puzzles and helps us better understand Spinoza's arguments for some of his most famous doctrines, including his parallelism doctrine and his theory of sense perception. It also undermines a widespread view about the relationship between the three fundamental, undefined notions in Spinoza's metaphysics: causation, conception and inherence.

I will develop a new problem for almost all realist theories of colour. The problem involves fluctuations in our colour experiences that are due to visual noise rather than changes in the objects we are looking at.

I suggest a solution to two puzzles in Spinoza's metaphysics. The first puzzle involves the mind and the idea of the mind, in particular how they can be identical, even though the mind thinks about bodies and nothing else, whereas the idea of the mind thinks about ideas and nothing else. The second puzzle involves the mind and the idea of a thing that belongs to an unknown attribute, in particular how they can be identical, even though the mind thinks (...) about bodies and nothing else, whereas the idea thinks about things belonging to the unknown attribute and nothing else. I suggest that Spinoza would respond to both puzzles by rejecting the Indiscernibility of Identicals. (shrink)

Conception and causation are fundamental notions in Spinoza's metaphysics. I argue against the orthodox view that, due to the causal axiom, if one thing is conceived through another thing, then the second thing causes the first thing. My conclusion forces us to rethink Spinoza's entitlement to some of his core commitments, including the principle of sufficient reason, the parallelism doctrine and the conatus doctrine.

This commentary shall focus on the central claim made in Lynch et al.’s paper “Promoting Ethical Payment in Human Infection Challenge Studies.” According to their paper, there is a threefold...

There is variation in how people perceive colors and other secondary qualities. The challenge of perceptual variation is to say whose perceptions are accurate. A natural and influential response is that, whenever there’s variation in two people’s perceptions, at most one of their perceptions is accurate. I will argue that this leads to an unacceptable kind of ignorance.

Indispensability arguments are used as a way of working out what there is: our best science tells us what things there are. Some philosophers think that indispensability arguments can be used to show that we should be committed to the existence of mathematical objects (numbers, functions, sets). Do indispensability arguments also deliver conclusions about the modal properties of these mathematical entities? Colyvan (in Leng, Paseau, Potter (eds) Mathematical knowledge, OUP, Oxford, 109-122, 2007) and Hartry Field (Realism, mathematics and modality, Blackwell, (...) Oxford, 1989) each suggest that a consequence of the empirical methodology of indispensability arguments is that the resulting mathematical objects can only be said to exist (or not exist) contingently. Kristie Miller has argued that this line of thought doesn’t work (Miller in Erkenntnis, 77 (3), 335-359, 2012). Miller argues that indispensability arguments are in direct tension with contingentism about mathematical objects, and that they cannot tell us about the modal status of mathematical objects. I argue that Miller’s argument is crucially imprecise, and that the best way of making it clearer no longer shows that the indispensability strategy collapses or is unstable if it delivers contingentist conclusions about what there is. (shrink)

We extend recent conversation about the ethics of human challenge trials to tuberculosis (TB). TB challenge studies could accelerate vaccine development, but ethical concerns regarding risks to trial participants and third parties have been a limiting factor. We analyse the expected social value and risks of different challenge models, concluding that if a TB challenge trial has between a 10% and a 50% chance of leading to the authorisation and near-universal delivery of a more effective vaccine 3–5 years earlier, then (...) the trial would save between 26 400 and 1 100 000 lives over the next 10 years. We also identify five important ethical considerations that differentiate TB from recent human challenge trials: an exceptionally high disease burden with no highly effective vaccine; heightened third party risk following the trial, and, partly for that reason, uniquely stringent biosafety requirements for the trial; risks associated with best available TB treatments; and difficulties with TB disease detection. We argue that there is good reason to consider conducting challenge trials with attenuated strains like Bacillus Calmette-Guérin or attenuatedMycobacterium tuberculosis. (shrink)

Evidential holism begins with something like the claim that “it is only jointly as a theory that scientific statements imply their observable consequences.” This is the holistic claim that Elliott Sober tells us is an “unexceptional observation”. But variations on this “unexceptional” claim feature as a premise in a series of controversial arguments for radical conclusions, such as that there is no analytic or synthetic distinction that the meaning of a sentence cannot be understood without understanding the whole language of (...) which it is a part and that all knowledge is empirical knowledge. This paper is a survey of what evidential holism is, how plausible it is, and what consequences it has. Section 1 will distinguish a range of different holistic claims, Sections 2 and 3 explore how well motivated they are and how they relate to one another, and Section 4 returns to the arguments listed above and uses the distinctions from the previous sections to identify holism's role in each case. (shrink)

TB human challenge studies could accelerate TB vaccine development by reducing uncertainty in early-stage vaccine testing, selecting promising vaccine candidates for large-scale field trials, and identifying an immune correlate of protection. However, ethical concerns regarding the exposure of trial participants and bystanders to significant risk have been a limiting factor for TB human challenge models. We analyze the expected social value and risks of different types of TB human challenge models, and conclude that given the massive public health burden of (...) TB, challenge models with even scant probabilities of expediting TB vaccine authorization have enormous expected humanitarian value, saving between 33,000 and 1,375,000 lives over the next ten years. We argue that attenuated M.tb challenge trials can be conducted ethically, and discuss the benefits and drawbacks of conducting virulent M.tb challenge trials. (shrink)

Verbal autopsy presents the opportunity to understand the disease burden in many low-income countries where vital registration systems are underdeveloped and most deaths occur in the community. Advances in technology have led to the development of software that can provide probable cause of death information in real time, and research considering the ethical implications of these advances is necessary to inform policy. Our research explores these ethical issues in rural Nepal using a public health ethics framework. We considered the burdens (...) and benefits of VA and giving cause of death information to families of the deceased through qualitative research with VA interviewers, community members, national policy stakeholders and international academics. Burdens can be experienced differently, and it is important to balance the emotional burden of VA with utilization of the data to inform planning and increased access to health services. The training, support and supervision of VA interviewers should be prioritized if VA is taken to scale. Initial and ongoing community engagement is recommended in addition to engaging ethical, legal, health and policy personnel in developing protocols and systems. Integrating rigorous research while cautiously moving forward is recommended to ensure systems and responses to concerns are relevant to contexts. (shrink)

Ongoing and anticipated COVID-19 human challenge studies in the UK may advance our understanding of COVID-19 and facilitate the licensure of safe, effective, and easily deployable next-generation COVID-19 vaccines and boosters. We argue that international volunteer recruitment for COVID-19 human challenge trials can help promote diversity in these trials and ensure a sufficient number of eligible volunteers, both of which will increase the benefits of challenge research. We explore the ethical ramifications of dealing with unfair background conditions of global vaccine (...) injustice to expand medical research, and conclude that international recruitment for COVID-19 human challenge trials can be conducted ethically provided that several robust protections are in place for volunteers. (shrink)

There is variation in how people perceive colors and other secondary qualities. The challenge of perceptual variation is to say whose perceptions are accurate. According to Sextus, Protagoras’ response is that all of our perceptions might be accurate. As this response is traditionally developed, it is difficult to explain color illusion and color constancy. This difficulty is due to a widespread assumption called perceptual atomism. This chapter argues that, if we want to develop Protagoras’ response, we need to give up (...) perceptual atomism. It ends with a brief sketch of an alternative called perceptual structuralism. (shrink)

Antidoping policy regulates and punishes the use of substances that are listed on a Prohibited List (PL). These substances are colloquially known as ‘performance-enhancing substances’. There is very little empirical evidence of enhancement for most of the substances on the PL raising the possibility that the perceived enhancement of performance experienced by an athlete is a placebo effect. A placebo effect is a response to an inert substance that is strongly influenced by psychological and social cues in the surrounding environment. (...) It is our contention that, given the lack of proper empirical testing of the substances on the PL, it is in fact the appearance of a substance on the PL that has the strongest performance-enhancing effect in elite athletes. This disconnect between science and WADA’s code raises the question of what we really object to: real performance enhancement achieved using substances on the PL or performance enhancement that occurs because WADA has told us that the substance will enhance performance by placing it on the PL? In this case, antidoping policy would punish those who believe the performance-enhancing myth at the heart of the PL thus leading to a deeply flawed policy that creates its own victims. (shrink)

The anti-doping policies of the World Anti-Doping Agency (WADA) aim to promote a level playing field and protect the health of the athlete. Anti-doping policy discourages research using performance enhancing drugs (PEDs) or methods and prohibits athlete support personnel, including healthcare providers, from providing advice, assistance, or aid to an athlete or others seeking to use, or using PEDs until harm has occurred. Athletes are individually responsible for the presence of a prohibited substance in their bodies and face sanction regardless (...) of knowledge or intent. I will argue (i) that WADA policies fail to meet the epistemic and control conditions needed to adequately assign individual responsibility and (ii) that transferring responsibility for use of PEDs solely to the athlete results in harm. WADA is drifting perilously close to the morally impermissible ‘doing of harm’ to athletes by initiating or sustaining a causal sequence of events that can result in harm. (shrink)

Suppose you're unable to discriminate the colors of two objects. According to the triangulation view, their colors might nonetheless look different to you, and that's something you can discover as a result of further comparisons. The primary motivation for this view is its apparent ability to solve a puzzle involving a series of pairwise indiscriminable objects. I argue that, due to visual noise, the triangulation view doesn't really solve the puzzle.

Spinoza claims that a person's body can be numerically identical over time, despite changes in its size, shape, and speed. This chapter argues that he would reject the Indiscernibility of Identicals. The Indiscernibility of Identicals is often taken to have profound implications for one's view of change. Spinoza seems to deny the existence of times, because he similarly classifies them as “beings of reason”. As Spinoza understands instantiation, whenever a property is instantiated by an object, it metaphysically depends on that (...) object. As Spinoza understands instantiation, the existence of a property causally depends on whatever instantiates it. Spinoza says that the mind, and therefore the body, can “undergo great changes, and pass to a greater, to a lesser perfection”. Spinoza is committed to saying that all bodies are capable of change, even the shortest‐lived. Spinoza can deny that the non‐identity of Downstairs Peter and Upstairs Peter is due to their conflicting properties. (shrink)

According to most contemporary philosophers, the Indiscernibility of Identicals is obviously true. We might therefore expect earlier philosophers to endorse it. But I will use a puzzle about identity over time to argue that Descartes would reject it.

We establish that, due to certain quantum indeterminacies, there must be foundational colours that do not reliably cause any particular experience. This report functions as an appendix to Morrison's "Colour in a Physical World.".

A satisfactory contextualist theory of knowledge must provide an account of how knowledge varies across contexts. There are three contextualist proposals for developing such an account. This paper demonstrates that all of them are unacceptable. Contextualists have therefore failed to provide a satisfactory theory of knowledge.

The results of the Progress in International Reading Literacy Study (PIRLS 2001) were published in 2003. In addition to data about the reading achievements of 10?year?olds in 35 countries, PIRLS 2001 also collected questionnaire information from children, their teachers, headteachers and parents. The results showed not just how well students can perform in various reading tasks, but also the relationship between reading abilities and other characteristics, including the characteristics of their homes and schools, the students' attitudes to reading, reading enjoyment, (...) self?confidence, engagement and perceptions of their reading abilities. Surprisingly enough, children in England were reported as having poor attitudes to reading, compared to children in many other countries, despite high achievement on the reading tests. This paper raises some concerns about the interpretation of results from the study, suggesting a more complex picture than that presented in the summary index published in 2003. Our secondary analysis of the attitude and achievement data from PIRLS shows that pupils with low ability levels have misunderstood the questions which tested their attitudes towards reading. The authors point out that caution is needed when making cross?country comparisons to avoid naïve approaches to interpretation. (shrink)

A satisfactory contextualist theory of knowledge must provide an account of how knowledge varies across contexts. There are three contextualist proposals for developing such an account. This paper demonstrates that all of them are unacceptable. Contextualists have therefore failed to provide a satisfactory theory of knowledge.

Readers will learn what logic is, use truth tables and truth trees, make sense of complex arguments, and use logic every day.

A survey of arguments and positions concerning the possibility of inductive knowledge, this piece covers: Hume's problem of induction; the underdetermination of theories by evidence; the method of hypothesis; the relationship between underdetermination and evidential holism; attempts to specify how some statements can be said to be evidentially (or justificatorily) relevant to other claims.

A book review of Raffaella De Rosa's Descartes and the Puzzle of Sensory Representation".

A book review of Valtteri Viljanen's "Spinoza’s Geometry of Power".