Many realists argue that present scientific theories will not follow the fate of past scientific theories because the former are more successful than the latter. Critics object that realists need to show that present theories have reached the level of success that warrants their truth. I reply that the special theory of relativity has been repeatedly reinforced by unconceived scientific methods, so it will be reinforced by infinitely many unconceived scientific methods. This argument for the special theory of relativity overcomes (...) the critics’ objection, and has advantages over the no-miracle argument and the selective induction for it. (shrink)

Healey (2019a) makes four comments on my (Park, 2019a) objections to van Fraassen’s positions. The four comments concern the issues of whether ‘disbelief’ is appropriate or inappropriate to characterize van Fraassen’s position, what the relationship between a theory and models is for van Fraassen, whether he believes or not that a theory is empirically adequate, and whether destructive empiricism is tenable or not. I reply to those comments in this paper.

Throughout the COVID-19 pandemic, shortages of scarce healthcare resources consistently presented significant moral and practical challenges. While the importance of vaccines as a key pharmaceutical intervention to stem pandemic scarcity was widely publicized, a sizable proportion of the population chose not to vaccinate. In response, some have defended the use of vaccination status as a criterion for the allocation of scarce medical resources. In this paper, we critically interpret this burgeoning literature, and describe a framework for thinking about vaccine-sensitive resource (...) allocation using the values of responsibility, reciprocity, and justice. Although our aim here is not to defend a single view of vaccine-sensitive resource allocation, we believe that attending critically with the diversity of arguments in favor (and against) vaccine-sensitivity reveals a number of questions that a vaccine-sensitive approach to allocation should answer in future pandemics. (shrink)

A formulational debate is a debate over whether certain definitions of scientific realism and antirealism are useful or useless. By contrast, an epistemological debate is a debate over whether we have sufficient evidence for scientific realism and antirealism defined in a certain manner. I argue that Hilary Putnam’s definitions of scientific realism and antirealism are more useful than Bas van Fraassen’s definitions of scientific realism and constructive empiricism because Putnam’s definitions can generate both formulational and epistemological debates, whereas van Fraassen’s (...) can generate only formulational debates. (shrink)

The pessimistic induction holds that successful past scientific theories are completely false, so successful current ones are completely false too. I object that past science did not perform as poorly as the pessimistic induction depicts. A close study of the history of science entitles us to construct an optimistic induction that would neutralize the pessimistic induction. Also, even if past theories were completely false, it does not even inductively follow that the current theories will also turn out to be completely (...) false because the current theories are more successful and have better birth qualities than the past theories. Finally, the extra success and better birth qualities justify an anti-induction in favor of the present theories. (shrink)

The no-miracles argument (Putnam, 1975) holds that science is successful because successful theories are (approximately) true. Frost-Arnold (2010) objects that this argument is unacceptable because it generates neither new predictions nor unifications. It is similar to the unacceptable explanation that opium puts people to sleep because it has a dormative virtue. I reply that on close examination, realism explains not only why some theories are successful but also why successful theories exist in current science. Therefore, it unifies the disparate phenomena.

This book provides philosophers of science with new theoretical resources for making their own contributions to the scientific realism debate. Readers will encounter old and new arguments for and against scientific realism. They will also be given useful tips for how to provide influential formulations of scientific realism and antirealism. Finally, they will see how scientific realism relates to scientific progress, scientific understanding, mathematical realism, and scientific practice.

The epistemic account and the noetic account hold that the essence of scientific progress is the increase in knowledge and understanding, respectively. Dellsén (2018) criticizes the epistemic account (Park, 2017a) and defends the noetic account (Dellsén, 2016). I argue that Dellsén’s criticisms against the epistemic account fail, and that his notion of understanding, which he claims requires neither belief nor justification, cannot explain scientific progress, although it can explain fictional progress in science-fiction.

Nanay (2017) argues for unconscious mental imagery, inter alia based on the assumption that successful performance in imagery tasks requires the manipulation of mental imagery. I challenge this assumption with the help of results presented in Shepard and Metzler (1971), Zeman et al. (2010), and Keogh and Pearson (2018). The studies suggest that imagery tasks can be successfully performed by means of cognitive/propositional strategies which do not rely on imagery.

The pessimistic induction over scientific theories holds that present theories will be overthrown as were past theories. The pessimistic induction over scientists holds that present scientists cannot conceive of future theories just as past scientists could not conceive of present theories. The pessimistic induction over realists :4321–4330, 2013) holds that present realists are wrong about present theories just as past realists were wrong about past theories. The pessimistic induction over antirealist theories :3–21, 2014) holds that the latest antirealist explanation of (...) the success of science :891–901, 2003) has hidden problems just as its eight predecessors did. In this paper, I criticize the pessimistic inductions over scientific theories, scientists, and realists, introduce a pessimistic induction over antirealist theories, and then construct two new pessimistic inductions. One is a pessimistic induction over antirealists according to which the author of the latest antirealist proposal cannot see hidden problems with his proposal just as his antirealist predecessors could not see hidden problems with their proposals. The other is the pessimistic induction over pessimists according to which since past pessimists have been wrong about their present scientific theories from the early twentieth century to the early twenty-first century, future pessimists will also be wrong about their present scientific theories from the early twenty-first century to the early twenty-second century. (shrink)

Realism and surrealism claim, respectively, that a scientific theory is successful because it is true, and because the world operates as if it is true. Lyons :891–901, 2003) criticizes realism and argues that surrealism is superior to realism. I reply that Lyons’s criticisms against realism fail. I also attempt to establish the following two claims: Realism and surrealism lead to a useful prescription and a useless prescription, respectively, on how to make an unsuccessful theory successful. Realism and surrealism give the (...) credit for the success of a theory to an appropriate factor and to an inappropriate factor, respectively. Finally, I point out that surrealism is vulnerable to my pessimistic induction :3–21, 2014a) against antirealism. (shrink)

Dawes (2013) claims that we ought not to believe but to accept our best scientific theories. To accept them means to employ them as premises in our reasoning with the goal of attaining knowledge about unobservables. I reply that if we do not believe our best scientific theories, we cannot gain knowledge about unobservables, our opponents might dismiss the predictions derived from them, and we cannot use them to explain phenomena. We commit an unethical speech act when we explain a (...) phenomenon in terms of a theory we do not believe. (shrink)

Sample (2015) argues that scientists ought not to believe that their theories are true because they cannot fulfill the epistemic obligation to take the diachronic perspective on their theories. I reply that Sample’s argument imposes an inordinately heavy epistemic obligation on scientists, and that it spells doom not only for scientific theories but also for observational beliefs and philosophical ideas that Samples endorses. I also delineate what I take to be a reasonable epistemic obligation for scientists. In sum, philosophers ought (...) to impose on scientists only an epistemic standard that they are willing to impose on themselves. (shrink)

Selectivism holds that some theoretical contents of most present theories will be preserved in future theories. By contrast, optimistic realism holds that most theoretical contents of most present theories will be preserved in future theories. I construct a pessimistic induction over selectivists to undermine selectivism, and an optimistic induction over optimistic realists to support optimistic realism. The former holds that since the selectivists of the early twentieth century were overly cautious about their present theories, those of the early twenty-first century (...) are also overly cautious about their present theories. The latter holds that since the optimistic realists of the early twentieth century were right about their present theories, those of the early twenty-first century are also right about their present theories. (shrink)

Van Fraassen (1980) claims that successful theories exist today because successful theories survive and unsuccessful ones die. Wray (2007, 2010) appeals to Stanford’s new pessimistic induction (2006), arguing that van Fraassen’s selectionist explanation is better than the realist explanation that successful theories exist because they are approximately true. I argue that if the pessimistic induction is correct, then the evolutionary explanation is neither true nor empirically adequate, and that realism is better than selectionism because realism explains more phenomena in science (...) than selectionism. (shrink)

Nickles (2017) advocates scientific antirealism by appealing to the pessimistic induction over scientific theories, the illusion hypothesis (Quoidbach, Gilbert, and Wilson, 2013), and Darwin’s evolutionary theory. He rejects Putnam’s (1975: 73) no-miracles argument on the grounds that it uses inference to the best explanation. I object that both the illusion hypothesis and evolutionary theory clash with the pessimistic induction and with his negative attitude towards inference to the best explanation. I also argue that Nickles’s positive philosophical theories are subject to (...) Park’s (2017a) pessimistic induction over antirealists. (shrink)

What attitude should we take toward a scientific theory when it competes with other scientific theories? This question elicited different answers from instrumentalists, logical positivists, constructive empiricists, scientific realists, holists, theory-ladenists, antidivisionists, falsificationists, and anarchists in the philosophy of science literature. I will summarize the diverse philosophical responses to the problem of underdetermination, and argue that there are different kinds of underdetermination, and that they should be kept apart from each other because they call for different responses.

After decades of intense debate over the old pessimistic induction (Laudan, 1977; Putnam, 1978), it has now become clear that it has at least the following four problems. First, it overlooks the fact that present theories are more successful than past theories. Second, it commits the fallacy of biased statistics. Third, it erroneously groups together past theories from different fields of science. Four, it misses the fact that some theoretical components of past theories were preserved. I argue that these four (...) problems entitle us to construct what I call the grand pessimistic induction that since the old pessimistic induction has infinitely many hidden problems, the new pessimistic induction (Stanford, 2006) also has infinitely many hidden problems. (shrink)

Bird argues that scientific progress consists in increasing knowledge. Dellsén objects that increasing knowledge is neither necessary nor sufficient for scientific progress, and argues that scientific progress rather consists in increasing understanding. Dellsén also contends that unlike Bird’s view, his view can account for the scientific practices of using idealizations and of choosing simple theories over complex ones. I argue that Dellsén’s criticisms against Bird’s view fail, and that increasing understanding cannot account for scientific progress, if acceptance, as opposed to (...) belief, is required for scientific understanding. (shrink)

Putnam (1975) infers from the success of a scientific theory to its approximate truth and the reference of its key term. Laudan (1981) objects that some past theories were successful, and yet their key terms did not refer, so they were not even approximately true. Kitcher (1993) replies that the past theories are approximately true because their working posits are true, although their idle posits are false. In contrast, I argue that successful theories which cohere with each other are approximately (...) true, and that their key terms refer. My position is immune to Laudan’s counterexamples to Putnam’s inference and yields a solution to a problem with Kitcher’s position. (shrink)

If scientists embrace scientific realism, they can use a scientific theory to explain and predict observables and unobservables. If, however, they embrace scientific antirealism, they cannot use a scientific theory to explain observables and unobservables, and cannot use a scientific theory to predict unobservables. Given that explanation and prediction are means to make scientific progress, scientists can make more scientific progress, if they embrace scientific realism than if they embrace scientific antirealism.

Scientific realists and antirealists believe that a successful scientific theory is true and merely empirically adequate, respectively. In contrast, epistemic reciprocalists believe that realists’ positive theories are true, and that antirealists’ positive theories are merely empirically adequate, treating their target agents as their target agents treat other epistemic agents. Antirealists cannot convince reciprocalists that their positive theories are true, no matter how confident they might be that they are true. In addition, reciprocalists criticize antirealists’ positive theories exactly in the way (...) that antirealists criticize their epistemic colleagues’ theories. Reciprocalism is a better epistemic policy than realism and antirealism in the epistemic battleground in which we strive to be epistemically safe vis-à-vis our epistemic colleagues’ theories and strive to convince our epistemic colleagues that our theories are true. (shrink)

Scientific realists claim that the best of successful rival theories is (approximately) true. Relative realists object that we cannot make the absolute judgment that a theory is successful, and that we can only make the relative judgment that it is more successful than its competitor. I argue that this objection is undermined by the cases in which empirical equivalents are successful. Relative realists invoke the argument from a bad lot to undermine scientific realism and to support relative realism. In response, (...) I construct the argument from double spaces. It is similar to the argument from a bad lot, but threatens many philosophical inferences, including relative realists’ inference from comparative success to comparative truth. (shrink)

The pessimistic induction is built upon the uniformity principle that the future resembles the past. In daily scientific activities, however, scientists sometimes rely on what I call the disuniformity principle that the future differs from the past. They do not give up their research projects despite the repeated failures. They believe that they will succeed although they failed repeatedly, and as a result they achieve what they intended to achieve. Given that the disuniformity principle is useful in certain cases in (...) science, we might reasonably use it to infer that present theories are true unlike past theories. Hence, pessimists have the burden to show that our prediction about the fate of present theories is more likely to be true if we use the uniformity principle than if we use the disuniformity principle. (shrink)

Individual realism asserts that our best scientific theories are (approximately) true. In contrast, selective realism asserts that only the stable posits of our best scientific theories are true. Hence, individual realism recommends that we accept more of what our best scientific theories say about the world than selective realism does. The more scientists believe what their theories say about the world, the more they are motivated to exercise their imaginations and think up new theories and experiments. Therefore, individual realism better (...) fosters scientific creativity than selective realism. (shrink)

Externalists argue that motivation is external to moral judgments on the grounds that people can be unmoved by their moral judgments. I reply that people sometimes act indifferently to their moral considerations not because their moral judgments lack motivation but because their moral judgments are obstructed by rival desires. It appears that the moral motivation wanes while the moral judgments linger. In reality, however, the moral motivation is only made inconspicuous by the motivation of the opposing desires. A moral judgment (...) is subject to obstruction just like an emotive judgment and a gustatory judgment. (shrink)

Localism is the view that the unit of evaluation in the scientific realism debate is a single scientific discipline, sub-discipline, or claim, whereas individualism is the view that the unit of evaluation is a single scientific theory. Localism is compatible, while individualism is not, with a local pessimistic induction and a local selective induction. Asay presents several arguments to support localism and undercut globalism, according to which the unit of evaluation is the set of all scientific disciplines. I argue that (...) some of his arguments clash with localism as well as with globalism and support individualism, and that individualism goes hand in hand, while localism does not, with the basic rule of how to evaluate an argument. (shrink)

Extensional scientific realism is the view that each believable scientific theory is supported by the unique first-order evidence for it and that if we want to believe that it is true, we should rely on its unique first-order evidence. In contrast, intensional scientific realism is the view that all believable scientific theories have a common feature and that we should rely on it to determine whether a theory is believable or not. Fitzpatrick argues that extensional realism is immune, while intensional (...) realism is not, to the pessimistic induction. I reply that if extensional realism overcomes the pessimistic induction at all, that is because it implicitly relies on the theoretical resource of intensional realism. I also argue that extensional realism, by nature, cannot embed a criterion for distinguishing between believable and unbelievable theories. (shrink)

The problem of unconceived alternatives can be undermined, regardless of whether the possibility space of alternatives is bounded or unbounded. If it is bounded, pessimists need to justify their assumption that the probability that scientists have not yet eliminated enough false alternatives is higher than the probability that scientists have already eliminated enough false alternatives. If it is unbounded, pessimists need to justify their assumption that the probability that scientists have not yet moved from the possibility space of false alternatives (...) to the possibility space of true alternatives is higher than the probability that scientists have already moved from the former to the latter space. (shrink)

In contemporary philosophy of science, the no-miracles argument and the pessimistic induction are regarded as the strongest arguments for and against scientific realism, respectively. In this paper, I construct a new argument for scientific realism which I call the anti-induction for scientific realism. It holds that, since past theories were false, present theories are true. I provide an example from the history of science to show that anti-inductions sometimes work in science. The anti-induction for scientific realism has several advantages over (...) the no-miracles argument as a positive argument for scientific realism. (shrink)

Van Fraassen does not merely perform Bayesian conditionalization on his pragmatic theory of scientific explanation; he uses inference to the best explanation (IBE) to justify it, contrary to what Prasetya thinks. Without first using IBE, we cannot carry out Bayesian conditionalization, contrary to what van Fraassen thinks. The argument from a bad lot, which van Fraassen constructs to criticize IBE, backfires on both the pragmatic theory and Bayesian conditionalization, pace van Fraassen and Prasetya.

Suppose that scientific realists believe that a successful theory is approximately true, and that constructive empiricists believe that it is empirically adequate. Whose belief is more likely to be false? The problem of underdetermination does not yield an answer to this question one way or the other, but the pessimistic induction does. The pessimistic induction, if correct, indicates that successful theories, both past and current, are empirically inadequate. It is arguable, however, that they are approximately true. Therefore, scientific realists overall (...) take less epistemic risk than constructive empiricists. (shrink)

Scientific realists argue that present theories are more successful than past theories, so present theories will not be superseded by alternatives, even though past theories were superseded by alternatives. Alai (2016) objects that although present theories are more successful than past theories, they will be replaced by future theories, just as past theories were replaced by present theories. He contends, however, that past theories were partly true, and that present theories are largely true. I argue that Alai’s discrimination between past (...) and present theories is subject to his own criticism against realists’ discriminations between past and present theories, and also subject to other criticisms that philosophers have raised against scientific realism and pessimism. (shrink)

Van Fraassen (2007, 2017) consistently uses the English view of rationality to parry criticisms from scientific realists. I assume for the sake of argument that the English view of rationality is tenable, and then argue that it has disastrous implications for van Fraassen’s (1980) contextual theory of explanation, for the empiricist position that T is empirically adequate, and for scientific progress. If you invoke the English view of rationality to rationally disbelieve that your epistemic colleagues’ theories are true, they might, (...) in turn, invoke it to rationally disbelieve that your positive theories are true. (shrink)

Both the pessimistic inductions over scientific theories and over scientists are built upon what I call proportional pessimism: as theories are discarded, the inductive rationale for concluding that the next theories will be discarded grows stronger. I argue that proportional pessimism clashes with the fact that present theories are more successful than past theories, and with the implications of the assumptions that there are finitely and infinitely many unconceived alternatives. Therefore, the two pessimistic inductions collapse along with proportional pessimism.

There are nine antirealist explanations of the success of science in the literature. I raise difficulties against all of them except the latest one, and then construct a pessimistic induction that the latest one will turn out to be problematic because its eight forerunners turned out to be problematic. This pessimistic induction is on a par with the traditional pessimistic induction that successful present scientific theories will be revealed to be false because successful past scientific theories were revealed to be (...) false. (shrink)

Dellsén (2016a) argues that understanding requires neither justification nor belief. I object that ridding understanding of justification and belief comes with the following costs. (i) No claim about the world can be inferred from what we understand. (ii) We run into either Moore’s paradox or certain disconcerting questions. (iii) Understanding does not represent the world. (iv) Understanding cannot take the central place in epistemology. (v) Understanding cannot be invoked to give an account of scientific progress. (vi) It is not clear (...) how misunderstanding arises. (shrink)

The ethical question is whether university mask mandates should be relaxed. I argue that the use of face masks by healthy individuals has uncertain benefits, which potential harms may outweigh, and should therefore be voluntary. Systematic reviews by the World Health Organization (WHO) and Cochrane Acute Respiratory Infections concluded that the use of face masks by healthy individuals in the community lacks effectiveness in reducing viral transmission based on moderate-quality evidence. The only two randomized controlled trials of face masks published (...) during the pandemic found little to no benefit. Without high-quality evidence, it is difficult to justify a requirement rather than a recommendation. Notwithstanding, one might argue that the precautionary principle justifies mask mandates. If the precautionary principle can justify implementing mask mandates due to the risk of forgoing possible benefit, then it might also be able to justify not implementing mask mandates due to the risk of potential harm caused by the intervention. It is commonly thought that there is little to lose from the use of face masks, but this is not necessarily true. It is possible that masks have done more harm than good. (shrink)

I raise the following six moral objections to the way God evaluates us. (i) He violates the human right to free thought. (ii) He makes the dubious assumption that it is praiseworthy and blameworthy, respectively, to believe and disbelieve that he exists. (iii) He excessively rewards believers and excessively punishes disbelievers. (iv) He only assigns to his evaluatees the two extreme grades: eternal bliss and eternal damnation. (v) He overlooks diverse factors related to the belief of God. (vi) He is (...) silent on the issue of whether to evaluate animals. Therefore, God, who is allegedly omnipotent, omniscient, and omnibenevolent, does not exist. (shrink)

Scientific realists believe both what a scientific theory says about observables and unobservables. In contrast, scientific antirealists believe what a scientific theory says about observables, but not about unobservables. I argue that scientific realism is a more useful doctrine than scientific antirealism in science classrooms. If science teachers are antirealists, they are caught in Moore’s paradox when they help their students grasp the content of a scientific theory, and when they explain a phenomenon in terms of a scientific theory. Teachers (...) ask questions to their students to check whether they have grasped the content of a scientific theory. If the students are antirealists, they are also caught in Moore’s paradox when they respond positively to their teachers’ questions, and when they explain a phenomenon in terms of a scientific theory. Finally, neither teachers nor students can understand phenomena in terms of scientific theories, if they are antirealists. (shrink)

According to realists, theories are successful because they are true, but according to selectionists, theories are successful because they have gone through a rigorous selection process. Wray claims that the realist and selectionist explanations are rivals to each other. Lee objects that they are instead complementary to each other. In my view, Lee’s objection presupposes that the realist explanation is true, and thus it begs the question against selectionists. By contrast, the selectionist explanation invokes a scientific theory, and thus it (...) is not clear whether it is a realist explanation or an antirealist explanation. Finally, the six new arguments for scientific realism in the literature truly complement the no-miracles argument. (shrink)

Does science move toward truths? Are present scientific theories (approximately) true? Should we invoke truths to explain the success of science? Do our cognitive faculties track truths? Some philosophers say yes, while others say no, to these questions. Interestingly, both groups use the same scientific theory, viz., evolutionary theory, to defend their positions. I argue that it begs the question for the former group to do so because their positive answers imply that evolutionary theory is warranted, whereas it is self-defeating (...) for the latter group to do so because their negative answers imply that evolutionary theory is unwarranted. (shrink)

Van Fraassen infers the truth of the contextual theory from his observation that it has passed a crucial test. Mizrahi infers the comparative truth of our best theories from his observation that they are more successful than their competitors. Their inferences require, according to the argument from double spaces, the prior belief that it is more likely that their target theories were pulled out from the T-space than from the O-space. The T-space is the logical space of unconceived theories whose (...) appearances agree with their realities; the O-space is the logical space of unconceived theories whose appearances may agree or disagree with their realities. (shrink)

Scientific antirealists run the argument from underconsideration against scientific realism. I argue that the argument from underconsideration backfires on antirealists’ positive philosophical theories, such as the contextual theory of explanation (van Fraassen, 1980), the English model of rationality (van Fraassen, 1989), the evolutionary explanation of the success of science (Wray, 2008; 2012), and explanatory idealism (Khalifa, 2013). Antirealists strengthen the argument from underconsideration with the pessimistic induction against current scientific theories. In response, I construct a pessimistic induction against antirealists that (...) since antirealists generated problematic philosophical theories in the past, they must be generating problematic philosophical theories now. (shrink)

In light of rampant fake news and disinformation in today's press and social media, I provide a new consequentialist argument that regulations on the media pertaining to certain false verifiable empirical facts are warranted. This contention is based in part on a collection of pre-existing empirical findings that I newly piece together from political science and psychology demonstrating that a post-truth society is likely with current media. My position is then defended from several counters, such as that it violates deontological (...) rights to free speech and to freedom of the press, that free speech leads to the acquisition of truth, and that government regulators can be biased and corrupt. (shrink)

I attempt to rebut the following standard objections against cultural relativism: 1. It is self-defeating for a cultural relativist to take the principle of tolerance as absolute; 2. There are universal moral rules, contrary to what cultural relativism claims; 3. If cultural relativism were true, Hitler’s genocidal actions would be right, social reformers would be wrong to go against their own culture, moral progress would be impossible, and an atrocious crime could be made moral by forming a culture which approves (...) of it; 4. Cultural relativism is silent about how large a group must be in order to be a culture, and which culture we should follow when we belong to two cultures with conflicting moralities. (shrink)

Van Fraassen explains rejections and asymmetries in science in terms of his contextual theory of explanation in the same way that scientists explain observable phenomena in the world in terms of scientific theories. I object that van Fraassen’s skeptical view regarding inference to the best explanation together with the English view of rationality jointly imply that the contextual theory is not rationally compelling, so van Fraassen and his epistemic colleagues can rationally disbelieve it. Prasetya replies that the truth of the (...) contextual theory coincides with its empirical adequacy, so the contextual theory is compelling. He also replies that the contextual theory is compelling, provided that van Fraassen’s argument for it instantiates a compelling subset of IBE. I argue that Prasetya’s replies either fail or help scientific realism. (shrink)

Van Fraassen contends that there is no argument that rationally compels us to disbelieve a successful theory, T. I object that this contention places upon him the burden of showing that scientific antirealists’ favorite arguments, such as the pessimistic induction, do not rationally compel us to disbelieve T. Van Fraassen uses the English view of rationality to rationally disbelieve T. I argue that realists can use it to rationally believe T, despite scientific antirealists’ favorite arguments against T.

This paper defends a theory of speech act that I call concurrentism. It consists of the following three theses. 1. We believe, ceteris paribus, that other people’s speech acts concur with their beliefs. 2. Our speech acts, ceteris paribus, concur with our beliefs. 3. When our speech acts deviate from our beliefs, we do not, ceteris paribus, declare the deviations to other people. Concurrentism sheds light on what the hearer believes when he hears an indicative sentence, what the speaker believes (...) when he says an indicative sentence, what the speaker does after he says an indicative sentence contrary to what he believes, why Moore’s paradox occurs, why it is puzzling to say some variants of Moorean sentences, and why it is not absurd to say other variants of Moorean sentences. (shrink)

Callard (2007) argues that it is metaphysically possible that a mathematical object, although abstract, causally affects the brain. I raise the following objections. First, a successful defence of mathematical realism requires not merely the metaphysical possibility but rather the actuality that a mathematical object affects the brain. Second, mathematical realists need to confront a set of three pertinent issues: why a mathematical object does not affect other concrete objects and other mathematical objects, what counts as a mathematical object, and how (...) we can have knowledge about an unchanging object. (shrink)