This paper defends the view, put roughly, that to think that p is to guess that p is the answer to the question at hand, and that to think that p rationally is for one’s guess to that question to be in a certain sense non-arbitrary. Some theses that will be argued for along the way include: that thinking is question-sensitive and, correspondingly, that ‘thinks’ is context-sensitive; that it can be rational to think that p while having arbitrarily low credence (...) that p; that, nonetheless, rational thinking is closed under entailment; that thinking does not supervene on credence; and that in many cases what one thinks on certain matters is, in a very literal sense, a choice. Finally, since there are strong reasons to believe that thinking just is believing, there are strong reasons to think that all this goes for belief as well. (shrink)

We analyze the notion of guessing model, a way to assign combinatorial properties to arbitrary regular cardinals. Guessing models can be used, in combination with inaccessibility, to characterize various large cardinal axioms, ranging from supercompactness to rank-to-rank embeddings. The majority of these large cardinal properties can be defined in terms of suitable elementary embeddings j:Vγ→Vλ. One key observation is that such embeddings are uniquely determined by the image structures j[Vγ]≺Vλ. These structures will be the prototypes guessing models. We shall show, (...) using guessing models M, how to prove for the ordinal κM=jM) many of the combinatorial properties that we can prove for the cardinal j) using the structure j[Vγ]≺Vj. κM will always be a regular cardinal, but consistently can be a successor and guessing models M with κM=ℵ2 exist assuming the proper forcing axiom. By means of these models we shall introduce a new structural property of models of PFA: the existence of a “Laver function” f:ℵ2→Hℵ2 sharing the same features of the usual Laver functions f:κ→Hκ provided by a supercompact cardinal κ. Further applications of our analysis will be proofs of the singular cardinal hypothesis and of the failure of the square principle assuming the existence of guessing models. In particular the failure of square shows that the existence of guessing models is a very strong assumption in terms of large cardinal strength. (shrink)

I develop a general framework with a rationality constraint that shows how coherently to represent and deal with second-order information about one's own judgmental reliability. It is a rejection of and generalization away from the typical Bayesian requirements of unconditional judgmental self-respect and perfect knowledge of one's own beliefs, and is defended by appeal to the Principal Principle. This yields consequences about maintaining unity of the self, about symmetries and asymmetries between the first- and third-person, and a principled way of (...) knowing when to stop second-guessing oneself. Peer disagreement is treated as a special case where one doubts oneself because of news that an intellectual equal disagrees. This framework, and variants of it, imply that the typically stated belief that an equally reliably peer disagrees is incoherent, and thus that pure rationality constraints without further substantive information cannot give an answer as to what to do. The framework also shows that treating both ourselves and others as thermometers in the disagreement situation does not imply the Equal Weight view. (shrink)

L. Jonathan Cohen; XI*—Guessing, Proceedings of the Aristotelian Society, Volume 74, Issue 1, 1 June 1974, Pages 189–210, https://doi.org/10.1093/aristotelian/7.

Ian Hacking; III—Guessing by Frequency, Proceedings of the Aristotelian Society, Volume 64, Issue 1, 1 June 1964, Pages 55–70, https://doi.org/10.1093/aristotel.

Evil and the fear coming along with it — either the fear to become its victim or its agent — is haunting mankind’s consciousness since the dawn of time. The powerful instinctive rejection that evil causes is only natural, and yet it prevents us from cognizing it and, thus, from building more effective defenses against it. Art sublimes the direct blow of our anxiety by transforming evil into symbolic and metaphorical figures which we can imaginably deal with and even accept (...) them, making them specifically interesting and even attractive. Along with artistic indulgence we strengthen the sense of metaphysical control over evil: Eventually shaping evil as a notion and an aggregative image we confirm to ourselves that we do have the ability to rise to the transcendent height of considering the Being as a Whole (or to the phenomenological essential insight), by doing so putting aside the limitations that conditio humana with its partiality and practical trivia lays upon us. Then again, presenting evil as an aesthetic phenomenon we design the kind of a virtual playground where we model it, counteract it and through this, finally establish our moral intuition on a new proven basis. Why is it so needed and reviving for us to create and use these psychological machines, not to mention the catharsis element they bring us, show some works of a prominent modern author Stephen King, the explorer of the theme of evil in the field of pop-culture. (shrink)

We survey the use of club guessing and other PCF constructs in the context of showing that a given partially ordered class of objects does not have a largest, or a universal, element.

We investigate club guessing sequences and filters. We prove that assuming V=L, there exists a strong club guessing sequence on μ if and only if μ is not ineffable for every uncountable regular cardinal μ. We also prove that for every uncountable regular cardinal μ, relative to the existence of a Woodin cardinal above μ, it is consistent that every tail club guessing ideal on μ is precipitous.

König, Larson and Yoshinobu initiated the study of principles for guessing generalized clubs, and introduced a construction of a higher Souslin tree from the strong guessing principle.Complementary to the author’s work on the validity of diamond and non-saturation at the successor of singulars, we deal here with a successor of regulars. It is established that even the non-strong guessing principle entails non-saturation, and that, assuming the necessary cardinal arithmetic configuration, entails a diamond-type principle which suffices for the construction of a (...) higher Souslin tree.We also establish the consistency of GCH with the failure of the weakest form of generalized club guessing. This, in particular, settles a question from the original paper. (shrink)

L. Jonathan Cohen; XI*—Guessing, Proceedings of the Aristotelian Society, Volume 74, Issue 1, 1 June 1974, Pages 189–210, https://doi.org/10.1093/aristotelian/7.

The article examines and extends work bringing together engineering ethics and Science and Technology Studies, which had built upon Diane Vaughan’s analysis of the Challenger shuttle accident as a test case. Reconsidering the use of her term “normalization of deviance,” the article argues for a middle path between moralizing against and excusing away engineering practices contributing to engineering disaster. To explore an illustrative pedagogical case and to suggest avenues for constructive research developing this middle path, it examines the emergence of (...) green chemistry and green engineering. Green chemistry began when Paul Anastas and John Warner developed a set of new rules for chemical synthesis that sought to learn from missed opportunities to avoid environmental damage in the twentieth century, an approach that was soon extended to engineering as well. Examination of tacit assumptions about historical counterfactuals in recent, interdisciplinary discussions of green chemistry illuminate competing views about the field’s prospects. An integrated perspective is sought, addressing how both technical practice within chemistry and engineering and the influence of a wider “social movement” can play a role in remedying environmental problems. (shrink)

I review the book “Making Prehistory: Historical Science and the Scientific Realism Debate” by Derek Turner. Turner suggests that philosophers should take seriously the historical sciences such as geology when considering philosophy of science issues. To that end, he explores the scientific realism debate with the historical sciences in mind. His conclusion is a view allied to that of Arthur Fine: a view Turner calls the natural historical attitude. While I find Turner’s motivations good, I find his characterisation of the (...) historical sciences unconvincing. I say why in a section at the end of the review. The result is that I am unpersuaded by his thesis. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Second GuessingAnonymous OneThis is difficult for me to write because I have tremendous respect for every doctor that has been involved in my son’s care. I firmly believe that they chose and administered the highest level of care that they assessed as appropriate; that they cared for him both personally and professionally as if he were their own child; and that he was in the care of acknowledged giants (...) in their fields. I write this knowing that I will share this narrative with these doctors, in order that they can better understand the decisions I was faced with and the guilt I must live with feeling that I may not have made the best possible informed choice for my son, because of this trust and relationship.Let me describe my oncologist. I say “my” instead of my son’s whose doctor he really is, because he is mine too in every sense of the word. He cares passionately about his work and about my son specifically; he engenders my trust because he is compassionate, brilliant, and available to me for concerns both great and small. His accomplishments have saved lives and will continue to impact his field. He became the narrow bridge I walk, that is the only thing between me and dangerous water and rocks waiting below; the balancing bar on the tightrope that is the only thing that stands to keep me from falling into the abyss and breaking my neck. And this made it difficult for me to disagree with him and seek a second opinion. Because his unspoken words were, “Don’t you trust me that I will do the best for your child?” and I could not answer then what I would answer now, “Nobody is infallible and sometimes we may miss something that someone else can see despite how much we know or care.”It is ironic, I think, that sometimes a layperson, because of her limited knowledge, can see more clearly where a professional may not.My son was diagnosed at age six with Grade II ependymoma in 2006. He was treated with surgery, a complete resection, and then 33 rounds of conformal radiation. He recurred in 2012, and was diagnosed with anaplastic ependymoma Grade III. He had another surgery, with the same surgeons, who pronounced it another successful total resection. This is where my story begins.The MRI taken the next day showed a sliver of something there. My oncologist, much sought after for his diagnostic abilities in reading MRI’s showed slight concern that it may be residual tumor, but both the surgeons and the MRI report came back negative, identifying the sliver as inflammation. Six [End Page 9] weeks later, 3 days before we were scheduled to leave out of town to receive proton beam radiation, I insisted on another MRI. The sliver was enlarged from the post–op MRI. My oncologist said it was tumor; one surgeon said it was inflammation and the other surgeon abstained from speculation. The MRI report stated it appeared to be recurrent tumor.Now here was my dilemma as a parent. The prognosis today of radiation on residual tumor for ependymomas is very bad, especially with a residual tumor of his size. On the other hand, my oncologist felt that going in for surgery with no guarantee of a total resection anyway, was incurring a risk of damage to my child that may impact severely on his quality of life.My oncologist felt that for many medical reasons, inherent risks of surgery, uncertainty about status of the scan reading, quality versus quantity of life, and—I think—an understandably pessimistic view of the possibility of cure for recurrent anaplastic grade III ependymoma, he was against another surgery, and opted to continue with radiation with the tumor as is.I am part of two support groups on line, one for parents of children with any type of brain tumor and the other specific for ependymoma parents. The clinical and anecdotal knowledge of these groups as a whole is phenomenal because, unfortunately, we have parents who have experienced and researched almost everything about this illness, in all its stages. When I was faced... (shrink)

“Scientific research faces up with an open and unknown world”Within the work of C. S. Peirce, the most fundamental and contentious form of inference is that of abduction. According to Peirce, abduction is the only type of inference from which new ideas are created (CP 5.171, 1903). He wrote, “every single item of scientific theory which stands established today has been due to Abduction” (CP 5.172, 1903). Similarly, “All that makes knowledge applicable comes to us viâ abduction. […] Not the (...) smallest advance can be made in knowledge beyond the stage of vacant staring, without making an abduction at every step” (HP 2:899–900, 1901). It is little wonder that so much attention has been paid to this particular type of.. (shrink)

Of the scientific concepts that the American philosopher, Charles S. Peirce, analyzed in his work, two of the less commonly investigated have been those of guessing and of scientific economy. Peirce argued that guessing was the initial moment of hypothesis-formation. He also argued that economic factors play a significant role in the development and acceptance of hypotheses; however, the relationship between these two concepts has been neglected in most philosophical and scientific literature. In the following, I provide an analysis of (...) how guessing and economic considerations contribute to hypothesis-formation. This analysis focuses primarily upon medical science; specifically, the epidemiology of HIV/AIDS. By using the first case studies in medical research that led to the ‘discovery’ of HIV/AIDS, I will argue that guessing is a tool utilized by researchers that is determined, at least in part, by implicit bias and economic considerations, which ultimately effect the trajectory of hypothesis-formation and the ensuing scientific research founded upon those hypotheses. In this particular case, both the biases of researchers and their effect upon economic considerations in the initial moments of guessing led to problematic hypotheses concerning the disease, populations susceptible to the disease, and how it was transmitted within that population. By recognizing how guessing and economy relate in this particular case and the functions of these conceptual tools as they relate to the isolation and discovery of disease, we can better understand epidemiological investigations and facilitate overcoming detrimental biases in such investigations. (shrink)

In the typical single-stimulus perceptual identification task, accuracy is improved by prior study of test words, a repetition priming benefit. There is also a cost, inasmuch as previously studied words are likely to be produced as responses if the test word is orthographically similar but not identical to a studied word. In two-alternative forced-choice perceptual identification, a test word is flashed and followed by two alternatives, one of which is the correct response. When the two alternatives are orthographically similar, test (...) words identical to previously studied items are identified more accurately than new words but tests words orthographically similar to studied words are identified less accurately than new words . Ratcliff and McKoon argue that these are bias effects that arise in the decision stage of word identification. We report five experiments that examined the alternative hypothesis that these bias effects arise from postperceptual guessing strategies. In single-stimulus perceptual identification, repetition priming benefits were equally great for young and older adults who claimed to use deliberate guessing strategies and those who did not . In contrast, only groups of young and older people who claimed to deliberately guess studied words in a two-alternative forced-choice task showed reliable benefits and costs. Costs and benefits were abolished in the two-alternative forced-choice task when a very long study list was used, presumably because the increased retrieval burden made the use of deliberate guessing strategies less attractive . Under conditions similar to those of Experiment 3, repetition priming was observed in single-stimulus perceptual identification . These results are consistent with the view that costs and benefits in the forced-choice perceptual identification task arise from deliberate guessing strategies but that those in the single-stimulus task do not. The possibility that the observed relationship between strategy reports and priming effects reflects erroneous postexperimental assessments of strategies by participants is also considered. (shrink)

Light and Kennison found that bias effects in the forced-choice perceptual identification of words occurred only in a subset of participants, those who claimed on a strategy questionnaire to be deliberately guessing words they had studied previously. McKoon and Ratcliff raised a number of objections to the proposal that bias effects are due to guessing strategies, citing difficulties in our statistical treatment of data, our use of subjective reports to classify participants, and our approach to the general problem of separating (...) implicit from explicit influences on performance. This article responds to these objections. (shrink)

In his dissertation, Wadge defined a notion of guessability on subsets of the Baire space and gave two characterizations of guessable sets. A set is guessable if and only if it is in the second ambiguous class, if and only if it is eventually annihilated by a certain remainder. We simplify this remainder and give a new proof of the latter equivalence. We then introduce a notion of guessing with an ordinal limit on how often one can change one’s mind. (...) We show that for every ordinal $\alpha$, a guessable set is annihilated by $\alpha$ applications of the simplified remainder if and only if it is guessable with fewer than $\alpha$ mind changes. We use guessability with fewer than $\alpha$ mind changes to give a semi-characterization of the Hausdorff difference hierarchy, and indicate how Wadge’s notion of guessability can be generalized to higher-order guessability, providing characterizations of ${\mathbf{\Delta}}^{0}_{\alpha}$ for all successor ordinals $\alpha\gt 1$. (shrink)

It is possible to control to a large extent, via semiproper forcing, the parameters measuring the guessing density of the members of any given antichain of stationary subsets of ω1 . Here, given a pair of ordinals, we will say that a stationary set Sω1 has guessing density if β0=γ and , where γ is, for every stationary S*ω1, the infimum of the set of ordinals τ≤ω1+1 for which there is a function with ot)<τ for all νS* and with {νS*:gF} (...) stationary for every α<ω2 and every canonical function g for α. This work involves an analysis of iterations of models of set theory relative to sequences of measures on possibly distinct measurable cardinals. As an application of these techniques I show how to force, from the existence of a supercompact cardinal, a model of in which there is a well-order of H definable, over H,, by a formula without parameters. (shrink)

We obtain very strong coloring theorems at successors of singular cardinals from failures of certain instances of simultaneous reflection of stationary sets. In particular, the simplest of our results establishes that if μ is singular and , then there is a regular cardinal θ<μ such that any fewer than cf stationary subsets of must reflect simultaneously.

This paper theoretically and experimentally investigates the behavior of asymmetric players in guessing games. The asymmetry is created by introducing r>1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$r>1$$\end{document} replicas of one of the players. Two-player and restricted N-player cases are examined in detail. Based on the model parameters, the equilibrium is either unique in which all players choose zero or mixed in which the weak player (r=1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$r=1$$\end{document}) imitates the strong (...) player (r>1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$r>1$$\end{document}). A series of experiments involving two and three-player repeated guessing games with unique equilibrium is conducted. We find that equilibrium behavior is observed less frequently and overall choices are farther from the equilibrium in two-player asymmetric games in contrast to symmetric games, but this is not the case in three-player games. Convergence towards equilibrium exists in all cases but asymmetry slows down the speed of convergence to the equilibrium in two, but not in three-player games. Furthermore, the strong players have a slight earning advantage over the weak players, and asymmetry increases the discrepancy in choices (defined as the squared distance of choices from the winning number) in both games. (shrink)

Starting with two supercompact cardinals we produce a generic extension of the universe in which a principle that we call GM+ holds. This principle implies ISP and ISP, and hence th...

I discuss a puzzle that arises as an apparent tension between plausible theories of good guessing and intuitive constraints on rational inquiry. Clearly, our best guess at a question should reflect the likelihoods we assign to its possible answers. Your best guess is the answer you judge most likely. Additionally, it seems like a requirement of rational inquiry that our guesses be coherent. Thus, our best guess to a constituent (wh-) questions should cohere with our best guess to a polar (...) (yes/no) question whenever answers to the former entail answers to the latter. I argue that these requirements are in conflict and that a familiar form of contextualism doesn’t resolve the issue. The puzzle stands as a challenge to existing accounts of rational inquiry and question directed attitudes like guessing. (shrink)

We outline the proof of the consistency that there exists a saturated tail club guessing ideal on ω₁ which is not a restriction of the nonstationary ideal. A new class of forcing notions and the forcing axiom for the class are introduced for this purpose.

It is shown in this paper that it is consistent (relative to almost huge cardinals) for various club guessing ideals to be saturated.

According to Karl Popper, the evolution of science, logically, methodologically, and even psychologically, is an involved interplay of acute conjectures and blunt refutations. Like biological evolution, it is an endless round of blind variation and selective retention. But unlike biological evolution, it incorporates, at the stage of selection, the use of reason. Part I of this two-part paper begins by repudiating the common beliefs that Hume’s problem of induction, which compellingly confutes the thesis that science is rational in the way (...) that most people think that it is rational, can be solved by assuming that science is rational, or by assuming that Hume was irrational (that is, by ignoring his argument). The problem of induction can be solved only by a non-authoritarian theory of rationality. It is shown also that because hypotheses cannot be distilled directly from experience, all knowledge is eventually dependent on blind conjecture, and therefore itself conjectural. In particular, the use of rules of inference, or of good or bad rules for generating conjectures, is conjectural. Part II of the paper expounds a form of Popper’s critical rationalism that locates the rationality of science entirely in the deductive processes by which conjectures are criticized and improved. But extreme forms of deductivism are rejected. The paper concludes with a sharp dismissal of the view that work in artificial intelligence, including the JSM method cultivated extensively by Victor Finn, does anything to upset critical rationalism. Machine learning sheds little light on either the problem of induction or on the role that logic plays in the development of scientific knowledge. (shrink)

According to Karl Popper, the evolution of science, logically, methodologically, and even psychologically, is an involved interplay of acute conjectures and blunt refutations. Like biological evolution, it is an endless round of blind variation and selective retention. But unlike biological evolution, it incorporates, at the stage of selection, the use of reason. Part I of this two-part paper begins by repudiating the common beliefs that Hume’s problem of induction, which compellingly confutes the thesis that science is rational in the way (...) that most people think that it is rational, can be solved by assuming that science is rational, or by assuming that Hume was irrational (that is, by ignoring his argument). The problem of induction can be solved only by a non-authoritarian theory of rationality. It is shown also that because hypotheses cannot be distilled directly from experience, all knowledge is eventually dependent on blind conjecture, and therefore itself conjectural. In particular, the use of rules of inference, or of good or bad rules for generating conjectures, is conjectural. Part II of the paper expounds a form of Popper’s critical rationalism that locates the rationality of science entirely in the deductive processes by which conjectures are criticized and improved. But extreme forms of deductivism are rejected. The paper concludes with a sharp dismissal of the view that work in artificial intelligence, including the JSM method cultivated extensively by Victor Finn, does anything to upset critical rationalism. Machine learning sheds little light on either the problem of induction or on the role that logic plays in the development of scientific knowledge. (shrink)

Iconicity, or the resemblance between form and meaning, is often ascribed to a special status and contrasted with default assumptions of arbitrariness in spoken language. But does iconicity in spoken language have a special status when it comes to learnability? A simple way to gauge learnability is to see how well something is retrieved from memory. We can further contrast this with guessability, to see (1) whether the ease of guessing the meanings of ideophones outperforms the rate at which they (...) are remembered; and (2) how willing participants’ are to reassess what they were taught in a prior task—a novel contribution of this study. We replicate prior guessing and memory tasks using ideophones and adjectives from Japanese, Korean, and Igbo. Our results show that although native Cantonese speakers guessed ideophone meanings above chance level, they memorized both ideophones and adjectives with comparable accuracy. However, response time data show that participants took significantly longer to respond correctly to adjective–meaning pairs—indicating a discrepancy in a cognitive effort that favored the recognition of ideophones. In a follow‐up reassessment task, participants who were taught foil translations were more likely to choose the true translations for ideophones rather than adjectives. By comparing the findings from our guessing and memory tasks, we conclude that iconicity is more accessible if a task requires participants to actively seek out sound‐meaning associations. (shrink)

Popper's methodology does not entail any playing down of the various indispensible distinctions such as the distinction between knowing and guessing, the distinction between myth and science, the distinction between the observational and the theoretical, and between the vernacular and technical sublanguages or technical vocabulary. By avoiding both the totalization that led to the foundationalist position and the scepticist reactions to these frustrated foundationalist hopes, Popper's methodology makes it possible to combine fallibilism with a realist view of theories. It combines (...) the perennial willingness to re-examine positions, statements, etc. with the claim that a particular theory (as an item of knowledge in the objective sense) constitutes cognitive progress over its rivals. However, some of his formulations have been deliberately provocative and in this way have given rise to certain misgivings about possible paradoxical implications, even in philosophers congenial with Popper's approach. The concept of knowledge in the objective sense is, of course, an explicatum which Popper proposes primarily for use in methodology and epistemology. The concept is an expression of the acknowledgment of fallibility in principle. The phrasing that ‘knowledge is conjectural’ or ‘knowledge is fallible’, even when it refers to knowledge in the objective sense, is but an abbreviation for: since our methods for ascertaining the truth-value of a particular statement about empirical reality are fallible in principle, there cannot be any certain knowledge about reality. In everyday life and in politics tolerance will be possible to the extent to which the recognition of this fallibility is more than a declaration. (shrink)

We investigate the interaction between compactness principles and guessing principles in the Radin forcing extensions. In particular, we show that in any Radin forcing extension with respect to a measure sequence on [Formula: see text], if [Formula: see text] is weakly compact, then [Formula: see text] holds. This provides contrast with a well-known theorem of Woodin, who showed that in a certain Radin extension over a suitably prepared ground model relative to the existence of large cardinals, the diamond principle fails (...) at a strongly inaccessible Mahlo cardinal. Refining the analysis of the Radin extensions, we consistently demonstrate a scenario where a compactness principle, stronger than the diagonal stationary reflection principle, holds yet the diamond principle fails at a strongly inaccessible cardinal, improving a result from [O. B. -Neria, Diamonds, compactness, and measure sequences, J. Math. Log. 19(1) (2019) 1950002]. (shrink)

A summary of The Rationality of Perception, and my replies to symposium papers on it by Andy Clark and Christopher Peacocke.

Popper's methodology does not entail any playing down of the various indispensible distinctions such as the distinction between knowing and guessing, the distinction between myth and science, the distinction between the observational and the theoretical, and between the vernacular and technical sublanguages or technical vocabulary. By avoiding both the totalization that led to the foundationalist position and the scepticist reactions to these frustrated foundationalist hopes, Popper's methodology makes it possible to combine fallibilism with a realist view of theories. It combines (...) the perennial willingness to re-examine positions, statements, etc. with the claim that a particular theory (as an item of knowledge in the objective sense) constitutes cognitive progress over its rivals. However, some of his formulations have been deliberately provocative and in this way have given rise to certain misgivings about possible paradoxical implications, even in philosophers congenial with Popper's approach. The concept of knowledge in the objective sense is, of course, an explicatum which Popper proposes primarily for use in methodology and epistemology. The concept is an expression of the acknowledgment of fallibility in principle. The phrasing that ‘knowledge is conjectural’ or ‘knowledge is fallible’, even when it refers to knowledge in the objective sense, is but an abbreviation for: since our methods for ascertaining the truth-value of a particular statement about empirical reality are fallible in principle, there cannot be any certain knowledge about reality. In everyday life and in politics tolerance will be possible to the extent to which the recognition of this fallibility is more than a declaration. (shrink)

Although the work consists of sixteen connected chapters, there is a difference of motivation that led to the book being published in two volumes. The first eleven chapters, comprising Volume I, attempt to teach good guessing through examples. The remaining chapters, in Volume II, deal with general principles of plausible reasoning.

We propose a two-step guessing game to measure the depth of thinking. We apply this method to the P beauty contest game. Using our method, we find that 81% of subjects do not make choice following best response reasoning while the classical method would suggest only 12%. The result suggests that the classical method has the fundamental problem that it cannot distinguish if a submitted number is due to best response reasoning or not. It also suggests that traditional level k (...) analysis falsely attributes some sophistication to random players, and that the degree of false attribution is large. Our procedure provides an alternative way to identify whether the individual has best response reasoning which is essential for any positive level of depth of thinking and differentiates between the depth of thinking and random choice, and hence provides a very different conclusion, which is suggestive of limitations of the classical method. (shrink)

In Chapter 3 of Judgment and Agency, Ernest Sosa (2015) explicates the concept of a fully apt performance. In the course of doing so, he draws from illustrative examples of practical performances and applies lessons drawn to the case of cognitive performances, and in particular, to the cog- nitive performance of judging. Sosa's examples in the practical sphere are rich and instructive. But there is, I will argue, an interesting disanalogy between the practical and cognitive examples he relies on. Ultimately, (...) I think the source of the disanalogy is a problematic picture of the cogni- tive performance of guessing and its connection to knowledge and defeat. Once this critical line of argument is advanced, an alternative picture of guessing, qua cognitive performance, is articulated, one which avoids the problems discussed, and yet remains compatible with Sosa's broader framework. (shrink)

Asking students to generate a prediction before presenting the correct answer is a popular instructional strategy. This study tested whether a person’s degree of confidence in a prediction is related to their curiosity and surprise regarding the answer. For a series of questions about numerical facts, participants (N = 29) generated predictions and rated their confidence in the prediction before seeing the correct answer. The increase in pupil size before viewing the correct answer was used as a physiological marker of (...) curiosity, and the increase in pupil size after viewing the correct answer was used as a physiological marker of surprise. The results revealed that the pupillometric marker of curiosity was most pronounced if students were slightly more confident in their prediction than usual, and it was lower for predictions made with either very high or very low confidence. Furthermore, the results showed that high-confidence prediction errors and low-confidence correct responses yielded a pupillary surprise response, suggesting that highly unexpected results evoke surprise, independent of the correctness of the prediction. Together, results suggest that confidence in a prediction plays an important role in the occurrence of epistemic emotions such as curiosity and surprise. (shrink)