Seungbae Park

Mathematical realism asserts that mathematical objects exist in the abstract world, and that a mathematical sentence is true or false, depending on whether the abstract world is as the mathematical sentence says it is. I raise two objections against mathematical realism. First, the abstract world is queer in that it allows for contradictory states of affairs. Second, mathematical realism does not have a theoretical resource to explain why a sentence about a tricle is true or false. A tricle is an object that changes its shape from a triangle to a circle, and then back to a triangle with every second.

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.

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.

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.

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.

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.

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.

Saatsi’s minimal realism holds that science makes theoretical progress. It is designed to get around the pessimistic induction, to fall between scientific realism and instrumentalism, and to explain the success of scientific theories. I raise the following two objections to it. First, it is not clear whether minimal realism lies between realism and instrumentalism, given that minimal realism does not entail instrumentalism. Second, it is not clear whether minimal realism can explain the success of scientific theories, given that it is doubtful that theoretical progress makes success likely. In addition to raising these two objections, I develop and criticize a new position that truly falls between realism and instrumentalism.

I criticize Kuhn’s (1962/1970) taxonomic incommensurability thesis as follows. (i) His argument for it is neither deductively sound nor inductively correct. (ii) It clashes with his account of scientific development that employs evolutionary theory. (iii) Even if two successive paradigms are taxonomically incommensurable, they have some overlapping theoretical claims, as selectivists point out. (iv) Since scientific revolutions were rare in the recent past, as historical optimists observe, they will also be rare in the future. Where scientific revolution is rare, taxonomic incommensurability is rare, and taxonomic commensurability is common. For these reasons, taxonomic commensurability rather than incommensurability should be advanced as an image of science.

Scientific antirealism, the view that successful theories are empirically adequate, is untenable in light of the problem of unobserved anomalies that since past scientists could not observe the anomalies that caused the replacement of past theories with present theories, present scientists also cannot observe the anomalies that will cause the replacement of present theories with future theories. There are several moves that antirealists would be tempted to make to get around the problem of unobserved anomalies. All of them, however, are problematic.

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.

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.

It is supererogatory to refrain from eating meat, just as it is supererogatory to refrain from driving cars, living in apartments, and wearing makeup, for the welfare of animals. If all animals are equal, and if nonhuman omnivores, such as bears and baboons, are justified in killing the members of other species, such as gazelles and buffaloes, for food, humans are also justified in killing the members of other species, such as cows, pigs, and chickens, for food. In addition, it is fair for humans to eat animals because humans are also eaten by animals.

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.

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.

McKitrick (2003) proposes that an object has a disposition if and only if there are a manifestation, the circumstances of the manifestation, a counterfactual true of the object, and an overtly dispositional locution referring to the disposition. A disposition is extrinsic if and only if an object has it, but a perfect duplicate of the object might not have it. I present an alternative definition that an object has a disposition if and only if a counterfactual is true of the object that under a certain condition, it would interact with another object in a certain manner. There are three reasons for thinking that my definition is better than her definition. 1. Ockham’s razor favors my definition over McKitrick’s definition. My definition is consistent, while her definition is not, with Lewis’s and her definitions of intrinsic and extrinsic properties. 3. My definition goes well, while her definition does not, with our intuition that an object has a disposition even in a possible world where there is nothing but that object.

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.

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.

Scientific realism (Putnam 1975; Psillos 1999) and relative realism (Mizrahi 2013) claim that successful scientific theories are approximately true and comparatively true, respectively. A theory is approximately true if and only if it is close to the truth. A theory is comparatively true if and only if it is closer to the truth than its competitors are. I argue that relative realism is more skeptical about the claims of science than it initially appears to be and that it can explain neither the success nor the failure of science. Hence, it is not a promising competitor to scientific realism.

Indispensablists argue that when our belief system conflicts with our experiences, we can negate a mathematical belief but we do not because if we do, we would have to make an excessive revision of our belief system. Thus, we retain a mathematical belief not because we have good evidence for it but because it is convenient to do so. I call this view ‘ mathematical convenientism.’ I argue that mathematical convenientism commits the consequential fallacy and that it demolishes the Quine-Putnam indispensability argument and Baker’s enhanced indispensability argument.

A scientific theory is successful, according to Stanford (2000), because it is suficiently observationally similar to its corresponding true theory. The Ptolemaic theory, for example, is successful because it is sufficiently similar to the Copernican theory at the observational level. The suggestion meets the scientific realists' request to explain the success of science without committing to the (approximate) truth of successful scientific theories. I argue that Stanford's proposal has a conceptual flaw. A conceptually sound explanation, I claim, respects the ontological order between properties. A dependent property is to be explained in terms of its underlying property, not the other way around. The applicability of this point goes well beyond the realm of the debate between scientific realists and antirealists. Any philosophers should keep the point in mind when they attempt to give an explanation of a property in their field whatever it may be.

This paper critically examines two objections and raises a new objection against the besire theory of moral judgment. Firstly, Smith (1994) observes that a belief that p tends to expire whereas a desire that p tends to endure on the perception that not p. His observation does not refute the sophisticated version of the besire theory that to besire that p is to believe that p and to desire to act in accordance with the belief that p. Secondly, Zangwill (2008) claims that the strength of motivation may vary while the degree of belief remains constant. Besirists would reply that a besire admits of both degree and strength. Finally, I argue that the belief that p endures while the desire to act on the belief that p expires with the introduction of a new bodily condition, and hence that the belief and the desire are distinct mental states.

I develop two problems, which I call the problem of divine location and the problem of divine age, to challenge the theist belief that God created the universe. The problem of divine location holds that it is not clear where God existed before he created the universe. The problem of divine age holds that it is not clear how old God was when he created the universe. I explore several theist responses to these two problems, and argue that all of them are problematic under the existing conceptions of space and time in physics. The philosophical magnitudes of these two problems are equal to that of the problem of evil.

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.

Cornea (2012) argues that I (2011) was wrong to use the analogy between morality and motion to defend cultural relativism. I reply that the analogy can be used to clarify what cultural relativism asserts and how a cultural relativist can reply to the criticisms against it. Ockham’s Razor favours the relativist view that there are no moral truths, and hence no culture is better than another. Contrary to what Cornea claims, cultural relativism does not entail that we cannot protect ourselves from those who attack us, and that the ruling of an international court lacks moral legitimacy.

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.

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.

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.

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.