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)

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)

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)

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)

The wider the gap between rivaling positions, the more there can be debates between rivaling interlocutors. The gap between the respective formulations of scientific realism and antirealism that invoke the Prussian conception of rationality is wider than the gap between the respective formulations of scientific realism and antirealism that invoke the English conception of rationality. Therefore, scientific realists and antirealists should choose the former over the latter as the framework of their debate.

Rival applied ethicists have constructed arguments for and against affirmative action independently of Rawls’s theory of justice. Those arguments do not resolve the dispute about affirmative action. I reformulate them with the use of Rawls’s theory of justice and conclude that the reformulated arguments do not resolve the dispute about affirmative action either. Therefore, Rawls’s theory of justice is not useful in resolving the dispute about affirmative action. This point applies to affirmative action in science, contrary to what some writers (...) suggest. (shrink)

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. (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)

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 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.

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.

In this paper, I reply to Markus Arnold’s comment and Amanda Bryant’s comment on my work “Can Kuhn’s Taxonomic Incommensurability be an Image of Science?” in Moti Mizrahi’s edited collection, The Kuhnian Image of Science: Time for a Decisive Transformation?. Philosophers and scientists are social epistemic agents. As such, they ought to behave in accordance with epistemic norms governing the behavior of social epistemic agents.

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)

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)

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. (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.

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. (shrink)

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. (shrink)

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. (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)

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)

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)

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)

Pessimists predict that future scientific theories will replace present scientific theories. However, they do not specify when the predicted events will take place, so we do not have the chance to blame them for having made a false prediction, although we might have the chance to praise them for having made a true prediction. Their predictions contrast with astronomers’ predictions. Astronomers specify when the next solar eclipse will happen, so we have both the chance to blame them for having made (...) a false prediction and the chance to praise them for having made a true prediction. The pessimists’ prediction remains unvirtuous until they specify when scientific revolutions will occur. This critical point applies no less to the selectivist’s prediction. (shrink)

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. (shrink)

I criticize the following three arguments for moral objectivism. 1. Since we assess moral statements, we can arrive at some moral truths (Thomson, 2006). 2. One culture can be closer to truths than another in moral matters because the former can be closer to truths than the latter in scientific matters (Pojman, 2008). 3. A moral judgment is shown to be true when it is backed up by reason (Rachels and Rachels, 2010). Finally, I construct a dilemma against the view (...) that there are moral truths and we can move toward them. (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)

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)

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)

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)

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)

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)

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.

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.

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)

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)

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)

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 (2016) 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)

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)

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)

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)

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.

Evolutionary theory coheres with its neighboring theories, such as the theory of plate tectonics, molecular biology, electromagnetic theory, and the germ theory of disease. These neighboring theories were previously unconceived, but they were later conceived, and then they cohered with evolutionary theory. Since evolutionary theory has been strengthened by its several neighboring theories that were previously unconceived, it will be strengthened by infinitely many hitherto unconceived neighboring theories. This argument for evolutionary theory echoes the problem of unconceived alternatives. Ironically, however, (...) the former recommends that we take the realist attitude toward evolutionary theory, while the latter recommends that we take the antirealist attitude toward it. (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)

We can judge whether some activities are scientific or religious, depending on how similar they are to exemplar scientific activities or to exemplar religious activities, even if we cannot specify the necessary and sufficient conditions for science and religion. The absence of the demarcation between science and religion does not justify the school policy of teaching the creationist hypothesis that God created the universe any more than it justifies the religious policy of teaching evolutionary theory, quantum mechanics, and the Big (...) Bang theory in religious institutions. -/- . (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)

Lyons (2016, 2017, 2018) formulates Laudan’s (1981) historical objection to scientific realism as a modus tollens. I present a better formulation of Laudan’s objection, and then argue that Lyons’s formulation is supererogatory. Lyons rejects scientific realism (Putnam, 1975) on the grounds that some successful past theories were (completely) false. I reply that scientific realism is not the categorical hypothesis that all successful scientific theories are (approximately) true, but rather the statistical hypothesis that most successful scientific theories are (approximately) true. Lyons (...) rejects selectivism (Kitcher, 1993; Psillos, 1999) on the grounds that some working assumptions were (completely) false in the history of science. I reply that selectivists would say not that all working assumptions are (approximately) true, but rather that most working assumptions are (approximately) true. (shrink)

Indispensablists contend that accepting scientific realism while rejecting mathematical realism involves a double standard. I refute this contention by developing an enhanced version of scientific realism, which I call interactive realism. It holds that interactively successful theories are typically approximately true, and that the interactive unobservable entities posited by them are likely to exist. It is immune to the pessimistic induction while mathematical realism is susceptible to it.

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)