The pessimistic induction,the flight to reference and the metaphysical zoo

Scientific realism says of our best scientific theories that (1) most of their important posits exist and (2) most of their central claims are approximately true. Antirealists sometimes offer the pessimistic induction in reply: since (1) and (2) are false about past successful theories, they are probably false about our own best theories too. The contemporary debate about this argument has turned (and become stuck) on the question, Do the central terms of successful scientific theories refer? For example, Larry Laudan offers a list of successful theories that employed central terms that failed to refer, and Philip Kitcher replies with a view about reference in which the central terms of such theories did sometimes refer. This article attempts to break this stalemate by proposing a direct version of the pessimistic induction, one that makes no explicit appeal to a substantive notion or theory of reference. While it is premature to say that this argument succeeds in showing that realism is probably false, the direct pessimistic induction is not subject to any kind of reference-based objection that might cripple a weaker, indirect version of the argument. Any attempt to trounce the direct pessimistic induction with a theory of reference fails.     

The pessimistic induction: a bad argument gone too far

In this paper, I consider the pessimistic induction construed as a deductive argument (specifically, reductio ad absurdum) and as an inductive argument (specifically, inductive generalization). I argue that both formulations of the pessimistic induction are fallacious. I also consider another possible interpretation of the pessimistic induction, namely, as pointing to counterexamples to the scientific realist’s thesis that success is a reliable mark of (approximate) truth. I argue that this interpretation of the pessimistic induction fails, too. If this is correct, then the pessimistic induction is an utter failure that should be abandoned by scientific anti-realists.     

Misperception of exponential growth

Exponential growth in numerical series and graphs is grossly underestimated in an intuitive extrapolation task. Subjects’ extrapolations are well described by a model with two parameters only: one for underestimation of the nonlinear growth, the other for linear compensation. The size of the effect is considerable; it is not unusual that two-thirds of the subjects produce estimates below 10% of the normative value. The effect increases with the exponent of the stimulus series, and with addition of a constant to the stimulus series. Neither special instructions about the nature of exponential growth nor daily experience with growth processes enhanced the extrapolations.

     

Forecasting exponential growth and exponential decline: similarities and differences

Previous research has demonstrated adults' difficulties with explicitly forecasting exponential processes. Exponential growth is usually grossly underestimated, whereas exponential decline is forecast more accurately. By contrast, the present study examined implicit knowledge about exponential processes and how it is affected by function type (growth versus decline) in samples of 7-, 10-, 14-year-olds, and adults (N=80). Different indicators of the quality of forecasts were investigated. As opposed to previous findings, participants of all age groups estimated exponential decline less adequately than exponential growth. This effect could be attributed mainly to the fact that, in relation to fitted exponential functions, the starting value, or intercept, of the function was approximated well for exponential growth but badly with regard to exponential decline. The accuracy of the non-linear component in forecast functions barely differed between function types within the same age group. Furthermore, even 7-year-olds appeared to have a preliminary understanding of exponential processes, while both intercepts and exponents of forecasts became more accurate with age. Theoretical and practical implications are discussed.     

Inverse statistics and misperception of exponential growth

Exponential growth presented by numerical series or graphs is grossly underestimated by human subjects. This misperception was considerably lessened by presenting decreasing functions; this conclusion holds for both numeric and graphic stimuli. In the numerical conditions, about 25% of the subjects performed according to the statistical norm. In contrast with previous results, considerable individual differences with respect to sensitivity for rate of growth were observed. This finding was interpreted in terms of task difficulty: Extrapolation of ascending series is too difficult a task to be discriminative. Extrapolation of descending series is much easier, and may therefore better discriminate among subjects.     

The pond-and-duckweed problem; Three experiments on the misperception of exponential growth

The representation of duckweed multiplying itself in a pond is used as a research paradigm to study underestimation of exponential growth. The advantage of this paradigm is that the growth process is presented in a direct non-numerical way. The results show that the underestimation observed in earlier studies where growth was presented by means of tables or graphs, occurs in the pond-and-duckweed situation as well. By manipulating the way the process is presented it is possible to obtain some insight into the sampling strategies used by the subjects when they subjectively extrapolate the perceived processes. These experiments lead to the conclusion that subjects base their extrapolations on three or four samples only.     

The sandwich effect reassessed: Effects of streaming, distraction, and modality

The degree of disruption from interleaving auditory irrelevant items within a sequence of to-be-remembered items--the sandwich effect--was examined in two experiments. Previous demonstrations of the effect have shown that the penalty for interleaving items is small and that changing irrelevant tokens is no more damaging than repeating ones (contrary to the classic changing state effect of irrelevant sound). The results of Experiment 1 suggest that these earlier results were due to the lack of tokens in the irrelevant sequence (in part, the result of using a span method). The results of Experiment 2 also show that the sandwich effect was marked and, further, that it comprised two elements, one due to the partitioning of relevant from irrelevant streams (which may be promoted by similarity of identity within sequence or pitch disparity between sequences), and the other a classic irrelevant sound effect (with effects of changing state). The results are discussed in terms of the role of perceptual organization within and between modalities in short-term memory.     

The pessimistic origin of Nietzsche’s thought of eternal recurrence

ABSTRACT

In this article I argue that we should understand Nietzsche’s doctrine of eternal recurrence as the ideal of life affirmation opposed to philosophical pessimism, the view that life is not worth living. I first articulate Nietzsche’s psychological account of pessimism as a vengeful focus on the past and an aversion to time understood as transience. I then consider the question of why a person with the opposite psychological orientation – a creative relation to the future and an endorsement of time – would will the eternal recurrence of all things. My answer appeals to Nietzsche’s notions of will to power and the redemption of the past from its senselessness. The interpretation of eternal recurrence that emerges from this approach takes Nietzsche’s vision of a great, world-redeeming individual to be integral to his doctrine of eternal recurrence. This is just one way in which it differs from common interpretations of eternal recurrence as a cosmological theory or thought experiment.     

How the growth of science ends theory change

This paper outlines a defense of scientific realism against the pessimistic meta-induction which appeals to the phenomenon of the exponential growth of science. Here, scientific realism is defined as the view that our current successful scientific theories are mostly approximately true, and pessimistic meta-induction is the argument that projects the occurrence of past refutations of successful theories to the present concluding that many or most current successful scientific theories are false. The defense starts with the observation that at least 80% of all scientific work ever done has been done since 1950, proceeds with the claim that practically all of our most successful theories were entirely stable during that period of time, and concludes that the projection of refutations of successful theories to the present is unsound. In addition to this defense, the paper offers a framework through which scientific realism can be compared with two types of anti-realism. The framework is also of help to examine the relationships between these three positions and the three main arguments offered respectively in their support (No-miracle argument, pessimistic meta-induction, underdetermination).     

The science and meaning of the self

Scientists and practitioners alike invest in theorizing the self in psychology, but prioritize differently theoretical and practical objectives. Theorizing the self differs also when mapped onto the 'science versus art' debate, viewed historically and with reference to the philosophy of science. Jung's model of the psyche is compared and contrasted with social cognitive models of self-concept. Finally, some implications of social constructionism are considered.     

Searching information on the Web and Planning Fallacy: A pilot investigation of pessimistic forecasts

IntroductionAccording to Planning Fallacy, people underestimate the time required to complete a task. A review of the social, cognitive, and motivational factors that moderate Planning Fallacy suggests that variability in Web searching tasks would lead to an overestimation of retrieval time, at least when the task duration is short (about 10 minutes).ObjectiveThe goals of this pilot study are twofold: to check the accuracy of forecasts when users estimate the time required to retrieve information on the Web, and to understand users’ strategies for dealing with the Web for multipurpose documentation.MethodParticipants (n = 32) were asked how long it would take to answer four encyclopedic questions on the Web; questions were in various fields with two levels of difficulty and two types of answers (qualitative vs quantitative). We compared estimations of the time required to retrieve specific information on the Web with the actual retrieval time. Forecasts were made before and after the effective retrieval task (within-subjects design).ResultsA significant and large overestimation of the anticipated time was observed, especially for questions with a qualitative answer. The overestimation range was between 195% and 473% for mean search durations between 4.5 and 10.3 min. Task perceived difficulty was the best predictor of time anticipation (r² < 0.32). Web search self-efficacy and experience contributed slightly to the overestimation but only for easy questions.ConclusionOverestimation of the time required to complete a Web searching task (i.e. pessimistic Planning Fallacy) results from a combination of factors: short length of tasks, variability in task difficulty, and the qualitative or quantitative nature of the correct answer. Search time forecast could be used as a benchmark to improve Web usability.