Fictional Persuasion and the Nature of Belief

Psychological studies on fictional persuasion demonstrate that being engaged with fiction systematically affects our beliefs about the real world, in ways that seem insensitive to the truth. This threatens to undermine the widely accepted view that beliefs are essentially regulated in ways that tend to ensure their truth, and may tempt various non-doxastic interpretations of the belief-seeming attitudes we form as a result of engaging with fiction. I evaluate this threat, and argue that it is benign. Even if the relevant attitudes are best seen as genuine beliefs, as I think they often are, their lack of appropriate sensitivity to the truth does not undermine the essential tie between belief and truth. To this end, I shall consider what I take to be the three most plausible models of the cognitive mechanisms underlying fictional persuasion, and argue that on none of these models does fictional persuasion undermine the essential truth-tie

Higher-Order Defeat and Doxastic Resilience

It seems obvious that when higher-order evidence makes it rational for one to doubt that one’s own belief on some matter is rational, this can undermine the rationality of that belief. This is known as higher-order defeat. However, despite its intuitive plausibility, it has proved puzzling how higher-order defeat works, exactly. To highlight two prominent sources of puzzlement, higher-order defeat seems to defy being understood in terms of conditionalization; and higher-order defeat can sometimes place agents in what seem like epistemic dilemmas. This chapter draws attention to an overlooked aspect of higher-order defeat, namely that it can undermine the resilience of one’s beliefs. The notion of resilience was originally devised to understand how one should reflect the ‘weight’ of one’s evidence. But it can also be applied to understand how one should reflect one’s higher-order evidence. The idea is particularly useful for understanding cases where one’s higher-order evidence indicates that one has failed in correctly assessing the evidence, without indicating whether one has over- or underestimated the degree of evidential support for a proposition. But it is exactly in such cases that the puzzles of higher-order defeat seem most compelling

Weighing the Aim of Belief Again

In his influential discussion of the aim of belief, David Owens argues that any talk of such an ‘aim’ is at best metaphorical. In order for the ‘aim’ of belief to be a genuine aim, it must be weighable with other aims in deliberation, but Owens claims that this is impossible. In previous work, I have pointed out that if we look at a broader range of deliberative contexts involving belief, it becomes clear that the putative aim of belief is capable of being weighed against other aims. Recently, however, Ema Sullivan-Bissett and Paul Noordhof have objected to this response on the grounds that it employs an undefended conception of the aim of belief not shared by Owens, and that it equivocates between importantly different contexts of doxastic deliberation. In this note, I argue that both of these objections fail

Nernst Effect as a Probe of Local Kondo Scattering in Heavy Fermions

A large, strongly temperature-dependent Nernst coefficient, $\nu$, is observed between $T$ = 2 K and 300 K for CeCu$_2$Si$_2$ and Ce$_{0.8}$La$_{0.2}$Cu$_2$Si$_2$. The enhanced $\nu(T)$ is determined by the asymmetry of the on-site Kondo (conduction electron$-4f$ electron) scattering rate. Taking into account the measured Hall mobility, $\mu_H$, the highly unusual thermopower, $S$, of these systems can be semiquantitatively described by $S(T)$ $=$ $-$$\nu(T)/\mu_H(T)$, which explicitly demonstrates that the thermopower originates from the local Kondo scattering process over a wide temperature range from far above to well below the coherence temperature ($\approx$ 20 K for CeCu$_2$Si$_2$). Our results suggest that the Nernst effect can act as a proper probe of local charge-carrier scattering. This promises an impact on exploring the unconventional enhancement of the thermopower in correlated materials suited for potential applications.Comment: 10 pages, 2 Figure

An Instrumentalist Account of How to Weigh Epistemic and Practical Reasons for Belief

When one has both epistemic and practical reasons for or against some belief, how do these reasons combine into an all-things-considered reason for or against that belief? The question might seem to presuppose the existence of practical reasons for belief. But we can rid the question of this presupposition. Once we do, a highly general ‘Combinatorial Problem’ emerges. The problem has been thought to be intractable due to certain differences in the combinatorial properties of epistemic and practical reasons. Here we bring good news: if we accept an independently motivated version of epistemic instrumentalism—the view that epistemic reasons are a species of instrumental reasons—we can reduce The Combinatorial Problem to the relatively benign problem of how to weigh different instrumental reasons against each other. As an added benefit, the instrumentalist account can explain the apparent intractability of The Combinatorial Problem in terms of a common tendency to think and talk about epistemic reasons in an elliptical manner

Glacier changes in the Bavarian Alps from 1989/90 to 2006/07

The five glaciers in Bavaria which today cover a total area of less than one square kilometer were frequently monitored by geodetic methods from the mid of the 20th century. In this paper, the record is extended by new surveys in 1999 and 2006. The glaciers show a prolonged surface lowering, which is intensified compared to the 1980s and reaches maximum rates from 1999-2006. Moreover, the ice thickness of four glaciers was determined in 2006 and 2007 by geophysical field techniques and allows the calculation of ice volumes. First simple extrapolations of observed volume losses indicate that the two Berchtesgaden glaciers and Südlicher Schneeferner could disappear by 2016, while the ice of Nördlicher Schneeferner endures until 2027. Ice thicknesses and surface changes are visualized in five annexed maps.Die fünf bayerischen Gletscher, die heute insgesamt eine Fläche von weniger als einem Quadratkilometer bedecken, wurden seit der Mitte des 20. Jahrhunderts regelmäßig geodätisch aufgenommen. Diese Reihe wird hier um zwei Neuvermessungen in den Jahren 1999 und 2006 erweitert. Alle Gletscher zeigen in dem Zeitraum eine fortgesetzte Erniedrigung ihrer Oberfläche, die im Vergleich zu den 1980er Jahren verstärkt ist und in der Periode 1999-2006 Maximalwerte aufzeigt. Außerdem wurden in den Jahren 2006 und 2007 die Eisdicken von vier Gletschern durch geophysikalische Messungen bestimmt, was erstmalig die Ermittlung des verbleibenden Eisvolumens erlaubt. Erste einfache Extrapolationen der beobachteten Volumenverluste in die Zukunft deuten an, dass die beiden Gletscher in den Berchtesgadener Alpen sowie der Südliche Schneeferner bis zum Jahr 2016 verschwinden könnten, während der Nördliche Schneeferner noch bis 2027 überdauern würde. Eisdicken und Oberflächenänderungen werden anhand von fünf Karten im Anhang verdeutlicht

Epistemic instrumentalism, permissibility, and reasons for belief

Epistemic instrumentalists seek to understand the normativity of epistemic norms on the model practical instrumental norms governing the relation between aims and means. Non-instrumentalists often object that this commits instrumentalists to implausible epistemic assessments. I argue that this objection presupposes an implausibly strong interpretation of epistemic norms. Once we realize that epistemic norms should be understood in terms of permissibility rather than obligation, and that evidence only occasionally provide normative reasons for belief, an instrumentalist account becomes available that delivers the correct epistemic verdicts. On this account, epistemic permissibility can be understood on the model of the wide-scope instrumental norm for instrumental rationality, while normative evidential reasons for belief can be understood in terms of instrumental transmission

Magnetization study on the field-induced quantum critical point in YbRh_2Si_2

We study the field-induced quantum critical point (QCP) in YbRh$_2$Si$_2$ by low-temperature magnetization, $M(T)$, and magnetic Gr\"uneisen ratio, $\Gamma_{\rm mag}$, measurements and compare the results with previous thermal expansion, $\beta(T)$, and critical Gr\"uneisen ratio, $\Gamma^{cr}(T)$, data on YbRh$_2$(Si$_{0.95}$Ge$_{0.05}$)$_2$. In the latter case, a slightly negative chemical pressure has been used to tune the system towards its zero-field QCP. The magnetization derivative $-dM/dT$ is far more singular than thermal expansion, reflecting a strongly temperature dependent pressure derivative of the field at constant entropy, $(dH/dP)_S=V_m\beta/(dM/dT)$ ($V_m$: molar volume), which saturates at $(0.15\pm 0.04)$ T/GPa for $T\to 0$. The line $T^\star(H)$, previously observed in Hall- and thermodynamic measurements, separates regimes in $T$-$H$ phase space of stronger $(\epsilon>1$) and weaker $(\epsilon<1$) divergent $\Gamma_{\rm mag}(T)\propto T^{-\epsilon}$.Comment: 4 Pages, 3 Figures, submitted to Proceedings of ICM 2009 (Karlsruhe