Gregor Betz

Reflective equilibrium (RE) is often regarded as a powerful method in ethics, logic, and even philosophy in general. Despite this popularity, characterizations of the method have been fairly vague and unspecific so far. It thus may be doubted whether RE is more than a jumble of appealing but ultimately sketchy ideas that cannot be spelled out consistently. In this paper, we dispel such doubts by devising a formal model of RE. The model contains as components the agent’s commitments and a theory that tries to systematize the commitments. It yields a precise picture of how the commitments and the theory are adjusted to each other. The model differentiates between equilibrium as a target state and the dynamic equilibration process. First solutions to the model, obtained by computer simulation, show that the method allows for consistent specification and that the model’s implications are plausible in view of expectations on RE. In particular, the mutual adjustment of commitments and theory can improve one’s commitments, as proponents of RE have suggested. We argue that our model is fruitful not only because it points to issues that need to be dealt with for a better understanding of RE, but also because it provides the means to address these issues.

There are different varieties of conservatism concerning belief formation and revision. We assesses the veritistic effects of a particular kind of conservatism commonly attributed to Quine: the so-called maxim of minimum mutiliation, which states that agents should give up as few beliefs as possible when facing recalcitrant evidence. Based on a formal bounded rationality model of belief revision, which parametrizes degree of conservatism, and corresponding multi-agent simulations, we eventually argue against doxastic conservatism from the vantage point of veritistic social epistemology.

If we want to understand how extremist group ideologies are established, we have to comprehend the social processes which form the basis of the emergence and distribution of such beliefs. In our chapter, we present an innovative approach to examining these processes and explaining how they function: with the method of computer-based simulation of opinion formation, we develop heuristic explanatory models which help to generate new and interesting hypotheses. The focus is thereby not on individuals and their idiosyncrasies but on the dynamic mutual adaptation of beliefs in a group. These dynamics can produce an incremental establishment of “charismatic” opinion leaders and an increasing radicalization and alienation. A prototype of such a simulation model has produced promising first results which are presented and discussed.

Philosophy of science attempts to reconstruct science as a rational cognitive enterprise. In doing so, it depicts a normative ideal of knowledge acquisition and does not primarily seek to describe actual scientific practice in an empirically adequate way. A comprehensive picture of what good science consists in may serve as a standard against which we evaluate and criticize actual scientific practices. Such a normative picture may also explain why it is reasonable for us to trust scientists – to the extent that they live up to the ideal – and to rely on their findings in decision making. Likewise, a sound normative understanding of science exposes the limits of scientific understanding and prevents us from placing blind faith in scientists and experts. For these reasons, philosophy of science represents a useful resource and background theory for the practice and study of science communication. In this handbook article, we provide an opinionated introduction to philosophy of science by flashing a light on 22 central issues which (we think) are of special interest to scholars and practitioners of science communication – and, in particular, to scholars and practitioners of external science communication.

With the evidence for anthropogenic climate change piling up, suggesting that climate impacts of GHG emissions might have been underestimated in the past (Allison et al. 2009; WBGU 2009), and mitigation policies apparently lagging behind what many scientists consider as necessary reductions in order to prevent dangerous climate change, the debate about intentional climate change, or “climate engineering”, as we shall say in the following, has gained momentum in the past years. While efforts to technically modify earth’s climate had been the focus of sporadic discussions at least since the White House’s Report “Restoring the Quality of Our Environment” (cf. Keith 2000), Paul Crutzen’s cautious plea for research into the feasibility and side-effects of stratospheric sulphur injections (Crutzen 2006) has incited an inter-disciplinary controversy (with a preliminary culmination in the Royal Society’s assessment (Royal Society 2009)), while increasing public awareness and debate about climate engineering, as well. The controversy, though, does not focus on the question whether climate engineering should be carried out today (which is largely reckoned to be a bad idea, unnecessary, or premature) or at some point in the future (which is considered a decision we don’t have to take now), but on whether to engage in large-scale research into the alternative technological options for carrying out intentional climate change. It is this paper’s purpose to make that controversy more transparent. In order to do so, we analyse what seems to be the major argument in favour of research into climate engineering: the lesser evil-, or, as Stephen Gardiner has called it, the arm the future-argument — in short: the AF-argument (Gardiner 2010). Such an argumentative analysis makes explicit the normative and descriptive assumptions which underlie the reasoning, without ascertaining or denying them, and thus enables one to assess the overall strength of the argument as well as to determine which objections do, and which don’t undermine it.

Dieser Beitrag diskutiert Oskar Morgensterns These von der Unmöglichkeit von Wirtschaftsprognose. Nach einer kritischen Rekonstruktion Morgensterns Argumente wird diese These in ihrer starken, apriorischen Lesart zurückgewiesen. Demgegenüber gestatten es die Ergebnisse empirischer Prognoseevaluationen, Morgensterns Überlegungen als kontingente Erklärungen des Scheiterns makroökonomischer Vorhersagen umzuinterpretieren. Der Beitrag schließt deshalb mit einer provokanten Konklusion, die bereits Morgenstern zog: der Forderung, Versuche makroökonomischer Vorhersage einzustellen.

This paper investigates in how far a theory of dialectical structures sheds new light on the old problem of giving a satisfying account of the fallacy of petitio principii, or begging the question. It defends that (i) circular argumentation on the one hand and petitio principii on the other hand are two distinct features of complex argumentation, and that (ii) it is impossible to make general statements about the defectiveness of an argumentation that exhibits these features. Such an argumentation, in contrast, has to be evaluated on a case-by-case basis. “Petitio principii”, this paper thence suggests, is one name for, in fact, a multitude of different and quite complex dialectical situations which require specific analysis and evaluation.

This paper shows how complex argumentation, analyzed as dialectical structures, can be evaluated within a Bayesian framework by interpreting them as coherence constraints on subjective degrees of belief. A dialectical structure is a set of arguments (premiss-conclusion structure) among which support- and attack-relations hold. This approach addresses the observation that some theses in a debate can be better justified than others and thus fixes a shortcoming of a theory of defeasible reasoning which applies the bivalence principle to argument evaluations by assigning them the status of being either defeated or undefeated. Evaluation procedures which are based on the principle of bivalence can, however, be embedded as a special case within the Bayesian framework. The approach developed in this paper rests on the assumptions that arguments can be reconstructed as deductively valid and that complex argumentation can be reconstructed such that premisses of arguments with equivalent conclusions are pairwise independent.

As climate policy decisions are decisions under uncertainty, being based on a range of future climate change scenarios, it becomes a crucial question how to set up this scenario range. Failing to comply with the precautionary principle, the scenario methodology widely used in the Third Assessment Report of the International Panel on Climate Change (IPCC) seems to violate international environmental law, in particular a provision of the United Nations Framework Convention on Climate Change. To place climate policy advice on a sound methodological basis would imply that climate simulations which are based on complex climate models had, in stark contrast to their current hegemony, hardly an epistemic role to play in climate scenario analysis at all. Their main function might actually consist in ‘foreseeing future ozone-holes’. In order to argue for these theses, I explain first of all the plurality of climate models used in climate science by the failure to avoid the problem of underdetermination. As a consequence, climate simulation results have to be interpreted as modal sentences, stating what is possibly true of our climate system. This indicates that climate policy decisions are decisions under uncertainty. Two general methodological principles which may guide the construction of the scenario range are formulated and contrasted with each other: modal inductivism and modal falsificationism. I argue that modal inductivism, being the methodology implicitly underlying the third IPCC report, is severely flawed. Modal falsificationism, representing the sound alternative, would in turn require an overhaul of the IPCC practice.

Epistemic trust figures prominently in our socio-cognitive practices. By assigning different degrees of competence to agents, we distinguish between experts and novices and determine the trustworthiness of testimony. This paper probes the claim that epistemic trust furthers our epistemic enterprise. More specifically, it assesses the veritistic value of competence attribution in an epistemic community, i.e., in a group of agents that collaboratively seek to track down the truth. The results, obtained by simulating opinion dynamics, tend to subvert the very idea that competence ascription is essential for the functioning of epistemic collaboration and hence veritistically valuable. On the contrary, we find that, in specific circumstances at least, epistemic trust may prevent a community from finding the truth effectively.

Wo Meinungen aufeinanderprallen, um Verständnis geworben und Überzeugungsarbeit geleistet wird, sind Begründungen nicht weit. Für jede Überzeugung gibt es immer ein, zwei Gründe, die mit Gegengründen konfrontiert und, im Gegenzug, mit weiteren Überlegungen verteidigt werden usw. usf. Schnell sind wir verwirrt und drohen, ohne uns der "Grammatikregeln" vernünftigen Argumentierens zu besinnen, nicht mehr durchzublicken. Die Theorie dialektischer Strukturen leistet einen Beitrag zur Grammatik vernünftigen Argumentierens. Sie stellt Begriffe und Verfahren bereit, um Fragen, die sich angesichts einer komplexen Argumentation stellen können, zu beantworten: Wie beziehen sich die einzelnen Argumente der Debatte aufeinander? Welche Positionen vertreten die verschiedenen Proponenten, und wie lassen sich diese bewerten? Wie gut ist die zentrale These der Kontroverse alles in allem begründet? Ist die und die Argumentationshandlung angesichts des Debattenstandes tatsächlich zweckmäßig und rational? Liegt hier eine zirkuläre - und damit fehlerhafte - Argumentation vor? Die klassische Logik, die sogenannte informal logic und argumentationstheoretische Ansätze der Künstlichen Intelligenz bilden Anknüpfungspunkte der Theorie dialektischer Strukturen. Exemplarisch werden die entwickelten argumentationstheoretischen Methoden zur Analyse umfangreicher philosophischer Kontroversen eingesetzt.

We use recently developed approaches in argumentation theory in order to revamp the hypothetico-deductive model of confirmation, thus alleviating the well-known paradoxes the H-D account faces. More specifically, we introduce the concept of dialectic confirmation on the background of the so-called theory of dialectical structures (Betz 2010, 2012b). Dialectic confirmation generalises hypothetico-deductive confirmation and mitigates the raven paradox, the grue paradox, the tacking paradox, the paradox from conceptual difference, and the problem of surprising evidence

Im Herbst des Jahres 20– breiten sich Gerüchte aus, dass am Genfer Kernforschungszentrum CERN, den gegenteiligen Versicherungen führender Teilchenphysiker zum Trotz, stabile schwarze Löcher erzeugt wurden. Daraufhin kommt es vielerorts zu Plünderungen. Auch vermelden zahlreiche Firmen und öffentliche Arbeitgeber, dass ein erheblicher Anteil der Belegschaft nicht am Arbeitsplatz erschienen ist. Rund um den Globus fragen sich Menschen ob der Hiobsbotschaften aus Genf: Steht nun der Weltuntergang tatsächlich kurz bevor? In der Sendung „Kontrovers“ im Deutschlandfunk diskutieren ein Teilchenphysiker, eine Juristin, ein Wissenschaftsjournalist und ein Philosoph diese Ereignisse. Wir freuen uns, hier einen Mitschnitt der Sendung vorab veröffentlichen zu können.

Climate policy decisions are decisions under uncertainty and are, therefore, based on a range of future climate scenarios, describing possible consequences of alternative policies. Accordingly, the methodology for setting up such a scenario range becomes pivotal in climate policy advice. The preferred methodology of the Intergovernmental Panel on Climate Change will be characterised as ,,modal verificationism"; it suffers from severe shortcomings which disqualify it for scientific policy advice. Modal falsificationism, as a more sound alternative, would radically alter the way the climate scenario range is set up. Climate science's inability to find robust upper bounds for future temperature rise in line with modal falsificationism does not disprove that methodology, rather, this very fact prescribes even more drastic efforts to curb CO2 emissions than currently proposed.

The Stern Review on The Economics of Climate Change is a highly influential welfare analysis of climate policy measures which has been published in 2006. This paper identifies and systematically assesses the long-term socioeconomic and climatic predictions the Stern Review relies on, and reflects them philosophically. Being a cost-benefit analysis, the Stern Review has to predict the benefits of climate mitigation policies, i.e.the damaging consequences of climate change which might be avoided, as well as the costs of implementing such policies. While distinguishing deterministic, probabilistic, and possibilisitic forecasts, this paper finds that the Review's major predictions severly suffer from a lack of robustness. It argues, moreover, that the use of subjective probabilities as well as the fact/value entanglement pose additional problems. Given our ignorance, this assessment raises finally the question how detailed an analysis of climate policy decisions should reasonably be at all, and whether the argument for acting against climate change is maybe very simple