Erik J. Wielenberg draws on recent work in analytic philosophy and empirical moral psychology to defend non-theistic robust normative realism, according to which there are objective ethical features of the universe that do not depend on God for their existence. He goes on to develop an empirically-grounded account of human moral knowledge.

The aim of this paper is to develop ideas about robustness analyses. I introduce a form of robustness analysis that I call sufficient parameter robustness, which has been neglected in the literature. I claim that sufficient parameter robustness is different from derivational robustness, the focus of previous research. My purpose is not only to suggest a new taxonomy of robustness, but also to argue that previous authors have concentrated on a narrow sense of (...) class='Hi'>robustness analysis, which they have inadequately distinguished from other investigations of models such as sensitivity analysis. (shrink)

A robust adaptive fuzzy nonlinear controller based on dynamic surface and integral sliding mode control strategy is proposed to realize trajectory tracking for a class of quadrotor UAVs. In this study, the composite factors including parametric uncertainties and external disturbances are added to controller design, which make it more realistic. The quadrotor model is divided into two subsystems of attitude and position that make the control design become feasible. The main contributions of the proposed ADSISMC strategy are as follows: The (...) combination of dynamic surface and integral sliding mode makes the system always in sliding stage by finding the appropriate initial position compared with the common sliding mode, and the complexity of explosion in backstepping method is eliminated. By introducing the fuzzy system, the unknown functions and uncertainties can be approximated which significantly improves the robustness and the tracking performance. The switching control strategy is utilized to compensate for the errors between estimated and ideal inputs; the tracking performance of the whole system has been significantly improved. The simulation results show the effectiveness of the proposed control method. (shrink)

This paper is aimed at identifying how a model’s explanatory power is constructed and identified, particularly in the practice of template-based modeling (Humphreys, Philos Sci 69:1–11, 2002; Extending ourselves: computational science, empiricism, and scientific method, 2004), and what kinds of explanations models constructed in this way can provide. In particular, this paper offers an account of non-causal structural explanation that forms an alternative to causal–mechanical accounts of model explanation that are currently popular in philosophy of biology and cognitive science. Clearly, (...) defences of non-causal explanation are far from new (e.g. Batterman, Br J Philos Sci 53:21–38, 2002a; The devil in the details: asymptotic reasoning in explanation, reduction, and emergence, 2002b; Pincock, Noûs 41:253–275, 2007; Mathematics and scientific representation 2012; Rice, Noûs. doi:10.1111/nous.12042, 2013; Biol Philos 27:685–703, 2012), so the targets here are focused on a particular type of robust phenomenon and how strong invariance to interventions can block a range of causal explanations. By focusing on a common form of model construction, the paper also ties functional or computational style explanations found in cognitive science and biology more firmly with explanatory practices across model-based science in general. (shrink)

Robustness is a common platitude: hypotheses are better supported with evidence generated by multiple techniques that rely on different background assumptions. Robustness has been put to numerous epistemic tasks, including the demarcation of artifacts from real entities, countering the “experimenter’s regress,” and resolving evidential discordance. Despite the frequency of appeals to robustness, the notion itself has received scant critique. Arguments based on robustness can give incorrect conclusions. More worrying is that although robustness may be valuable (...) in ideal evidential circumstances (i.e., when evidence is concordant), often when a variety of evidence is available from multiple techniques, the evidence is discordant. †To contact the author, please write to: Jacob Stegenga, Department of Philosophy, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093; e‐mail: [email protected]. (shrink)

This paper supports the literature which argues that derivational robustness can have epistemic import in highly idealized economic models. The defense is based on a particular example from mathematical economic theory, the dynamic Walrasian general equilibrium model. It is argued that derivational robustness first increased and later decreased the credibility of the Walrasian model. The example demonstrates that derivational robustness correctly describes the practices of a particular group of influential economic theorists and provides support for the arguments (...) of philosophers who have offered a general epistemic justification of such practices. (shrink)

Robustness arguments hold that hypotheses are more likely to be true when they are confirmed by diverse kinds of evidence. Robustness arguments require the confirming evidence to be independent. We identify two kinds of independence appealed to in robustness arguments: ontic independence —when the multiple lines of evidence depend on different materials, assumptions, or theories—and probabilistic independence. Many assume that OI is sufficient for a robustness argument to be warranted. However, we argue that, as typically construed, (...) OI is not a sufficient independence condition for warranting robustness arguments. We show that OI evidence can collectively confirm a hypothesis to a lower degree than individual lines of evidence, contrary to the standard assumption undergirding usual robustness arguments. We employ Bayesian networks to represent the ideal empirical scenario for a robustness argument and a variety of ways in which empirical scenarios can fall short of this ideal. (shrink)

In the philosophy of science and epistemology literature, robustness analysis has become an umbrella term that refers to a variety of strategies. One of the main purposes of this paper is to argue that different strategies rely on different criteria for justifications. More specifically, I will claim that: i) robustness analysis differs from de-idealization even though the two concepts have often been conflated in the literature; ii) the comparison of different model frameworks requires different justifications than the comparison (...) of models that differ only for the assumption under test; iii) the replacement of specific assumptions with different ones can encounter specific difficulties in scientific practice. These claims will be supported by a case study in population ecology and a case study in geographical economics. (shrink)

Derivational robustness may increase the degree to which various pieces of evidence indirectly confirm a robust result. There are two ways in which this increase may come about. First, if one can show that a result is robust, and that the various individual models used to derive it also have other confirmed results, these other results may indirectly confirm the robust result. Confirmation derives from the fact that data not known to bear on a result are shown to be (...) relevant when it is shown to be robust. Second, robustness may increase the degree to which the robust result is indirectly confirmed if it increases the weight with which existing evidence indirectly confirms it. This may happen when it strengthens the connection between the core and the robust result by showing that auxiliaries are not responsible for the result. (shrink)

When scientists seek further confirmation of their results, they often attempt to duplicate the results using diverse means. To the extent that they are successful in doing so, their results are said to be robust. This paper investigates the logic of such "robustness analysis" [RA]. The most important and challenging question an account of RA can answer is what sense of evidential diversity is involved in RAs. I argue that prevailing formal explications of such diversity are unsatisfactory. I propose (...) a unified, explanatory account of diversity in RAs. The resulting account is, I argue, truer to actual cases of RA in science; moreover, this account affords us a helpful, new foothold on the logic undergirding RAs. (shrink)

Robustness is often presented as a guideline for distinguishing the true or real from mere appearances or artifacts. Most of recent discussions of robustness have focused on the kind of derivational robustness analysis introduced by Levins, while the related but distinct idea of robustness as multiple accessibility, defended by Wimsatt, has received less attention. In this paper, I argue that the latter kind of robustness, when properly understood, can provide justification for ontological commitments. The idea (...) is that we are justified in believing that things studied by science are real insofar as we have robust evidence for them. I develop and analyze this idea in detail, and based on concrete examples show that it plays an important role in science. Finally, I demonstrate how robustness can be used to clarify the debate on scientific realism and to formulate new arguments. (shrink)

I propose a distinct type of robustness, which I suggest can support a confirmatory role in scientific reasoning, contrary to the usual philosophical claims. In model robustness, repeated production of the empirically successful model prediction or retrodiction against a background of independentlysupported and varying model constructions, within a group of models containing a shared causal factor, may suggest how confident we can be in the causal factor and predictions/retrodictions, especially once supported by a variety of evidence framework. I (...) present climate models of greenhouse gas global warming of the 20th Century as an example, and emphasize climate scientists’ discussions of robust models and causal aspects. The account is intended as applicable to a broad array of sciences that use complex modeling techniques. (shrink)

Non-reductive physicalists have made a number of attempts to provide the relation of supervenience between levels of properties with enough bite to analyze interesting cases without at the same time losing the relation's acceptability for the physicalist. I criticize some of these proposals and suggest an alternative supplementation of the supervenience relation by imposing a requirement of robustness which is motivated by the notion of structural stability familiar from dynamical systems theory. Robust supervenience, I argue, captures what the non-reductive (...) physicalist wants from supervenience; most importantly, it provides a natural background for reconstructing the notion of (diachronic) property emergence in a way acceptable to physicalists. (shrink)

Robustness may increase the degree to which the robust result is indirectly confirmed if it is shown to depend on confirmed rather than disconfirmed assumptions. Although increasing the weight with which existing evidence indirectly confirms it in such a case, robustness may also be irrelevant for confirmation, or may even disconfirm. Whether or not it confirms depends on the available data and on what other results have already been established.

Robustness properties of three equality of variances tests, the jackknife procedure, the k-sample Box-Andersen test, and Levene’s z test, were investigated and compared in a Monte Carlo study employing small samples from underlying gamma distributions and gamma mixtures. Overall, the jackknife test yielded rejection proportions usually closer to nominal levels under departures from normality, but the Box-Andersen test performed relatively well when departures from normality were not extreme. Four recommendations regarding testing variances were offered.

Contemporary analytic philosophy can generally be characterized by the following tendencies: commitment to first-order predicate logic as the only viable formal logic; rejection of correspondence theories of truth; a view of existence as something expressed by the existential quantifier; a metaphysics that doesnOCOt give the world as a whole its due. This book seeks to offer an alternative analytic theory, one that provides a unified account of what there is, how we speak about it, the underlying logic of our language, (...) how the truth of what we say is determined, and the central role of the real world in all of this. The result is a robust account of reality. The inspiration for many of the ideas that constitute this overall theory comes from such sources as Aristotle, Leibniz, Ryle, and Sommers.". (shrink)

In this paper, we propose a person verification scheme using a novel combination of palmprint and speech. The crucial aspect of biometric based verification lies in its use of features in verification. Thus, in this paper, we propose two novel feature extraction methods for palmprint verification. The proposed methods are based on the Gaussian mixture model followed by subspace based approaches such as ICA I and ICA II, called independent component analysis I mixture model and independent component analysis II mixture (...) model for palmprint verification. The speech verification system uses sphericity based measurement for person verification. The proposed multimodal biometric system uses a fairly large database of 150 users. The robustness of the proposed methods is validated by introducing six different types of noises on palmprint images and Gaussian white noise with two different signal-to-noise ratios on speech samples. Then, fusion of palmprint and speech are carried out at match score level using the weighted SUM rule for both clean and noisy conditions. Finally, we compare the results of combined biometric with the results of individual biometric and also the results of the proposed methods against conventional subspace methods. (shrink)

The concordance of results that are “robust” across multiple scientific modalities is widely considered to play a critical role in the epistemology of science. But what should we make of those cases where such multimodal evidence is discordant? Jacob Stegenga has recently argued that robustness is “worse than useless” in these cases, suggesting that “different kinds of evidence cannot be combined in a coherent way.” In this article I respond to this critique and illustrate the critical methodological role that (...) robustness plays as an aim of scientific inquiry. (shrink)

I distinguish two broad approaches to vagueness that I call "robust" and "wimpy". Wimpy construals explain vagueness as robust (i.e., does not manifest arbitrary precision); that standard approaches to vagueness, like supervaluationism or appeals to degrees of truth, wrongly treat vagueness as wimpy; that vagueness harbors an underlying logical incoherence; that vagueness in the world is therefore impossible; and that the kind of logical incoherence nascent in vague terms and concepts is benign rather than malignant. I describe some implications for (...) logic, semantics, and metaphysics. (shrink)

According to robust virtue epistemology, knowledge is a cognitive achievement, where this means that the agent's cognitive success is because of her cognitive ability. One type of objection to robust virtue epistemology that has been put forward in the contemporary literature is that this view has problems dealing with certain kinds of testimonial knowledge, and thus that it is in tension with standard views in the epistemology of testimony. We build on this critique to argue that insofar as agents epistemically (...) depend on third-party members of their epistemic community as many social epistemologists contend, then there will be cases where two agents differ epistemically despite being virtue-theoretic duplicates. This means that robust virtue epistemology, at least insofar as it is understood along standard lines such that it endorses epistemic individualism, is also in tension with a central commitment of contemporary social epistemology. (shrink)

Odenbaugh and Alexandrova provide a challenging critique of the epistemic benefits of robustness analysis, singling out for particular criticism the account we articulated in Kuorikoski et al.. Odenbaugh and Alexandrova offer two arguments against the confirmatory value of robustness analysis: robust theorems cannot specify causal mechanisms and models are rarely independent in the way required by robustness analysis. We address Odenbaugh and Alexandrova’s criticisms in order to clarify some of our original arguments and to shed further light (...) on the properties of robustness analysis and its epistemic rationale. (shrink)

Robustness is a pervasive property of living systems, instantiated at all levels of the biological hierarchies. As several other usual concepts in evolutionary biology, such as plasticity or dominance, it has been questioned from the viewpoint of its consequences upon evolution as well as from the side of its causes, on an ultimate or proximate viewpoint. It is therefore equally the explanandum for some enquiries in evolution in ecology, and the explanans for some interesting evolutionary phenomena such as evolvability. (...) This epistemological fact instantiates general property of biological evolution that I call “explanatory reversibility”. In this chapter, I attempt to systematize the explanatory projects regarding robustness by distinguishing a set of epistemological questions. Are they the various expressions of one general project with specific key concepts and methods, or very disparate epistemic projects, unified by the mere homonymy of the term “robustness”? More precisely, are there specific kinds of explanations suited to explain robustness? Finally, how does robustness as an explanandum connect with other explananda in which evolutionists have been massively interested recently such as complexity, modularity or evolvability? After having initially explored various meanings of the concept of robustness and surveyed its instances in biology, I will propose a distinction between mechanical and structural explanations of robustness in evolutionary and functional biology. Then, among the latter, I will highlight the class of “topological explanations,” and the subclass of explanations based on networks, as a major explanatory tool to address robustness. Focusing on evolutionary issues, I will eventually address the “explanatory reversibility” of robustness and consider its relation to key evolutionary concepts that are also explanatorily revertible such as modularity, evolvability and complexity. (shrink)

In robustness analysis, hypotheses are supported to the extent that a result proves robust, and a result is robust to the extent that we detect it in diverse ways. But what precise sense of diversity is at work here? In this paper, I show that the formal explications of evidential diversity most often appealed to in work on robustness – which all draw in one way or another on probabilistic independence – fail to shed light on the notion (...) of diversity relevant to robustness analysis. I close by briefly outlining a promising alternative approach inspired by Horwich’s (1982) eliminative account of evidential diversity. (shrink)

This paper addresses a variant of the job shop scheduling problem with total tardiness minimization where task durations and due dates are uncertain. This uncertainty is modelled with intervals. Different ranking methods for intervals are considered and embedded into a genetic algorithm. A new robustness measure is proposed to compare the different ranking methods and assess their capacity to predict ‘expected delays’ of jobs. Experimental results show that dealing with uncertainty during the optimization process yields more robust solutions. A (...) sensitivity analysis also shows that the robustness of the solutions given by the solving method increases when the uncertainty grows. (shrink)

Considering the effect of the local topology structure of an edge on cascading failures, we investigate the cascading reaction behaviors on scale-free networks with respect to small edge-based initial attacks. Our aim is to explore the relationship between some parameters and universal robustness characteristics against cascading failures on scale-free networks. We find by the theoretical analysis that the Baraba'si-Albert (BA) scale-free networks can reach the strongest robustness level against cascading failures when α + β = 1, where the (...) robustness is quantified by a transition from normal state to collapse. And the network robustness has a positive correlation with the average degree. We furthermore confirm by the numerical simulations these results. (shrink)

Philip Pettit offers a new insight into moral psychology. He shows that attachments such as love, and certain virtues such as honesty, require their characteristic behaviours not only as things actually are, but also in cases where things are different from how they actually are. He explores the implications of this idea for key moral issues.

According to robust moral realism, there exist objective, non-natural moral facts. Moral facts of this sort do not fit easily into the world as illuminated by natural science. Further, if such facts exist at all, it is hard to see how we could know of their existence by any familiar means. Yet robust realists are not moral skeptics; they believe that we do know the moral facts. Thus robust moral realism comes with a number of hard-to-defend ontological and epistemological commitments. (...) Recently, Sharon Street has claimed, in light of these commitments, that robust moral realism requires a kind of faith and “has become a strange form of religion.” I believe that Street is right. I argue at some length that robust moral realism does require faith, and is a religion. However, I further argue that it is an excellent religion. I argue that it has three principal advantages: it is avoids wishful thinking, is guaranteed not to contradict the results of natural science, and is profoundly simple in its ontological commitments. Further, robust moral realism may be rationally defensible on evidentialist grounds. Consequently, even if the standard arguments for traditional religions are not compelling, there might still be compelling arguments for robust moral realism. (shrink)

What is the nature of knowledge? A popular answer to that long-standing question comes from robust virtue epistemology, whose key idea is that knowing is just a matter of succeeding cognitively—i.e., coming to believe a proposition truly—due to an exercise of cognitive ability. Versions of robust virtue epistemology further developing and systematizing this idea offer different accounts of the relation that must hold between an agent’s cognitive success and the exercise of her cognitive abilities as well as of the very (...) nature of those abilities. This paper aims to give a new robust virtue epistemological account of knowledge based on a different understanding of the nature and structure of the kind of abilities that give rise to knowledge. (shrink)

We study a class of representation mechanisms, based on reports made by a random subset of agents, called representatives, in a collective choice problem with quasi-linear utilities. We do not assume the existence of a common prior probability describing the distribution of preference types. In addition, there is no benevolent planner. Decisions will be carried out by an individual who cannot be assumed impartial, a self-interested executive. These assumptions impose new constraints on Mechanism Design. A robust mechanism is defined as (...) maximizing expected welfare under a vague prior probability distribution, and over a set of mechanisms which is at the same time immune from opportunistic manipulations by the executive, and compatible with truthful revelation of preferences by representatives. Robust mechanisms are characterized and their existence is shown. Sampling Groves mechanisms are shown to be robust. (shrink)

We investigated the effect of distributed practice and more specifically the “lag effect” concerning the retention of mathematical procedures. The lag effect implies that longer retention intervals benefit from longer inter-study intervals (ISIs). University students ( N = 235) first learned how to solve permutation tasks and then practiced this procedure with an ISI of zero (i.e., massed), one, or 11 days. The final test took place after one or five weeks. All conditions were manipulated between-subjects. Contrary to our expectations, (...) the analyses revealed no effect of distributed practice and therewith also no lag effect, even though the sample size was sufficiently large. The only significant effect was that test performance was poorer after 5 weeks than after 1 week. In view of the present results and those of other studies, we assume that distributed practice works differently for declarative and procedural knowledge, with less robust of even absent effects when procedural skills are practiced with ISIs compared to massed practice. (shrink)

This paper considers the parametric control to the Lorenz system by state feedback. Based on the solutions of the generalized Sylvester matrix equation, the unified explicit parametric expression of the state feedback gain matrix is proposed. The closed loop of the Lorenz system can be transformed into an arbitrary constant matrix with the desired eigenstructure. The freedom provided by the parametric control can be fully used to find a controller to satisfy the robustness criteria. A numerical simulation is developed (...) to illustrate the effectiveness of the proposed approach. (shrink)

In the complex environment, the suddenly changing structural parameters and abrupt actuator failures are often encountered, and the negligence or unproper handling method may induce undesired or unacceptable results. In this paper, taking the suddenly changing structural parameters and abrupt actuator failures into consideration, we focus on the robust adaptive control design for a class of heterogeneous Takagi–Sugeno fuzzy nonlinear systems subjected to discontinuous multiple uncertainties. The key point is that the switch modes not only vary with the system time (...) but also vary with the system states, and the intrinsic heterogeneous characteristics make it difficult to design stable controllers. Firstly, the concepts of differential inclusion are introduced to describe the heterogeneous fuzzy systems. Meanwhile, a fundamental lemma is provided to demonstrate the criteria of the boundness for a Filippov solution. Then, by using the set-valued Lie derivative of the Lyapunov function and introducing a vector of specific continuous functions, the closed-loop T-S fuzzy differential inclusion systems are proved to be ultimately bounded. The sufficient conditions for system stability are derived in term of linear matrix inequalities, which can be solved directly. Finally, a numerical example is provided to illustrate the effectiveness of the proposed control algorithm. (shrink)

In this paper the theoretical power of the concept of robustness is discussed in order to characterize the argumentative competence of a speaker. This notion is countered with the extended use of the idea complexity. As a general background some empirical results are used to support the theoretical discussion. The paper mainly relies on the theory of cultural cognition to situate the category of robustness and offers particular criteria to specify the possible operationalization of the notion. These criteria (...) could later be applied, and even tested, in the analysis of other social behaviours that involve collective intentionality, cooperation and recursivity. En este trabajo se discute el alcance teórico del concepto robustez para caracterizar la competencia argumentativa de un hablante. Se contrapone la categoría al uso extendido de la idea de complejidad. Como referencia se utilizan algunos resultados empíricos para apoyar la discusión. El trabajo se apoya principalmente en el anclaje conceptual proveniente de la cognición cultural para situar la categoría robustez y ofrece criterios particulares que especifican la posible operacionalización de la noción, criterios que podrán luego ser aplicados, e incluso testeados, en el análisis de otros comportamientos sociales que involucran intencionalidad colectiva, cooperación y recursividad. (shrink)

Rasmussen (1993) argues that, because electron microscopists did not use robustness and would not have been warranted in using it as a criterion for the reality or the artifactuality of mesosomes, the bacterial mesosome serves as a test case for robustness that it fails. I respond by arguing that a more complete reading of the research literature on the mesosome shows that ultimately the more robust body of data did not support the mesosome and that electron microscopists used (...) and were warranted in using robustness as a criterion for the artifactuality of mesosomes. (shrink)

Prior research has shown that various types of conventional multiword chunks are processed faster than matched novel strings, but it is unclear whether this processing advantage extends to variant multiword chunks that are less formulaic. To determine whether the processing advantage of multiword chunks accommodates variations in the canonical phrasal template, we examined the robustness of the processing advantage (i.e., predictability) of binomial phrases with non‐canonical conjunctions (e.g.,salt and also pepper; salt as well as pepper). Results from the cloze (...) study (Experiment 1) showed that there was a high tendency of producing the canonical conjunct (pepper), even in the binomials that contained non‐formulaic conjunctions. Consistent with these findings, results from two eye tracking studies (Experiments 2a and 2b) showed that canonical conjuncts were read faster than novel conjuncts that were matched on word length (e.g.,paprika), even in the binomials with variant conjunctions. This robust online processing advantage was replicated in a self‐paced reading study that compared all three conjunction types (Experiment 3). Taken together, these findings show that binomials with variant function words also receive facilitated processing relative to matched novel strings, even though both types of strings are neither conventional nor relatively frequent. Exploratory analyses revealed that this processing speed advantage was driven by the lexical–semantic association between the canonical conjuncts (salt–pepper), rather than lexical and phrasal frequency. Overall, these results highlight flexibility in the processing of multiword chunks that current models of multiword storage and processing must take into account. (shrink)

In the presence of heterogeneity between the randomized controlled trial (RCT) participants and the target population, evaluating the treatment effect solely based on the RCT often leads to biased quantification of the real-world treatment effect. To address the problem of lack of generalizability for the treatment effect estimated by the RCT sample, we leverage observational studies with large samples that are representative of the target population. This article concerns evaluating treatment effects on survival outcomes for a target population and considers (...) a broad class of estimands that are functionals of treatment-specific survival functions, including differences in survival probability and restricted mean survival times. Motivated by two intuitive but distinct approaches, i.e., imputation based on survival outcome regression and weighting based on inverse probability of sampling, censoring, and treatment assignment, we propose a semiparametric estimator through the guidance of the efficient influence function. The proposed estimator is doubly robust in the sense that it is consistent for the target population estimands if either the survival model or the weighting model is correctly specified and is locally efficient when both are correct. In addition, as an alternative to parametric estimation, we employ the nonparametric method of sieves for flexible and robust estimation of the nuisance functions and show that the resulting estimator retains the root- n n consistency and efficiency, the so-called rate-double robustness. Simulation studies confirm the theoretical properties of the proposed estimator and show that it outperforms competitors. We apply the proposed method to estimate the effect of adjuvant chemotherapy on survival in patients with early-stage resected non-small cell lung cancer. (shrink)

The stabilization problem of a macroeconomic dynamical system is considered in this paper. The main features of this system are that the system uncertainties may be unknown functions of state and time but with known bounds. Furthermore, the control inputs are subject to constraints, which is a salient feature in an economic control problem. To ensure that the controls are within the specified boundaries, in our control design procedure, a creative diffeomorphism, which converts bounded controls into unbounded corresponding signals by (...) choosing an appropriate transformation function, is proposed. For the uncertain system, a deterministic robust control is designed to render the practical stability: uniform boundedness and uniform ultimate boundedness. The range of the input bounds is related to the uncertainties and can be designed according to the actual situation. Numerical simulations are performed to verify the effectiveness of the stabilization policy. (shrink)

This chapter discusses two different issues about the relationship between legal positivism and robust normativity (understood as the most authoritative kind of normativity to which we appeal). First, the chapter argues that, in many contexts when discussing “legal positivism” and “legal antipositivism”, the discussion should be shifted from whether legal facts are ultimately partly grounded in moral facts to whether they are ultimately partly grounded in robustly normative facts. Second, the chapter explores an important difference within the kinds of arguments (...) that legal philosophers give for the (purported) truth of legal positivism. The difference concerns whether (purportedly) robustly normative facts are appealed to as premises in those arguments or not. (A closely connected issue is whether (purportedly) normative facts that bear one or more important connections to robustly normative facts are appealed to in premises to those arguments.) The chapter argues that thinking about this dividing line helps people better situate the positivist/antipositivist dispute, better understand the space of views in legal philosophy, better evaluate those views, and avoid having merely verbal disputes. (shrink)

Robust Virtue Epistemology maintains that knowledge is achieved just when an agent gets to the truth through, or because of, the manifestation of intellectual virtue or ability. A notorious objection to the view is that the satisfaction of the virtue condition will be insufficient to ensure the safety of the target belief; that is, RVE is no anti-luck epistemology. Some of the most promising recent attempts to get around this problem are considered and shown to ultimately fail. Finally, a new (...) proposal for defending RVE as a kind of anti-luck epistemology is defended. The view developed here turns importantly on the idea that knowledge depends on ability and luck in a way that is gradient, not rigid, and that we know just when our cognitive success depends on ability not rather, but more so, than luck. (shrink)

Theorizing in ecology and evolution often proceeds via the construction of multiple idealized models. To determine whether a theoretical result actually depends on core features of the models and is not an artifact of simplifying assumptions, theorists have developed the technique of robustness analysis, the examination of multiple models looking for common predictions. A striking example of robustness analysis in ecology is the discovery of the Volterra Principle, which describes the effect of general biocides in predator-prey systems. This (...) paper details the discovery of the Volterra Principle and the demonstration of its robustness. It considers the classical ecology literature on robustness and introduces two individual-based models of predation, which are used to further analyze the Volterra Principle. The paper also introduces a distinction between parameter robustness, structural robustness, and representational robustness, and demonstrates that the Volterra Principle exhibits all three kinds of robustness. *Received September 2006; revised May 2007. ‡Earlier versions of this paper were presented at the Australasian Association of Philosophy, the London School of Economics, and the University of Bristol. The authors wish to thank those audiences as well as Patrick Forber, Ken Waters, Deena Skolnick Weisberg, Uri Wilensky, and Bill Wimsatt for many helpful comments. Special thanks to Giacomo Sillari for his assistance in translating Volterra's original paper and his insightful thoughts about Volterra's aims and methods. Some of the research in this paper was supported by NSF grant SES-0620887 to MW. †To contact the authors, please write to: Michael Weisberg, Department of Philosophy, University of Pennsylvania, 433 Logan Hall, Philadelphia, PA 19104; e-mail: [email protected]; Kenneth Reisman, Pluribo, Inc., 100 Park Avenue, Suite 1600, New York, NY 10017; e-mail: [email protected]. (shrink)

This paper argues that besides mechanistic explanations, there is a kind of explanation that relies upon “topological” properties of systems in order to derive the explanandum as a consequence, and which does not consider mechanisms or causal processes. I first investigate topological explanations in the case of ecological research on the stability of ecosystems. Then I contrast them with mechanistic explanations, thereby distinguishing the kind of realization they involve from the realization relations entailed by mechanistic explanations, and explain how both (...) kinds of explanations may be articulated in practice. The second section, expanding on the case of ecological stability, considers the phenomenon of robustness at all levels of the biological hierarchy in order to show that topological explanations are indeed pervasive there. Reasons are suggested for this, in which “neutral network” explanations are singled out as a form of topological explanation that spans across many levels. Finally, I appeal to the distinction of explanatory regimes to cast light on a controversy in philosophy of biology, the issue of contingence in evolution, which is shown to essentially involve issues about realization. (shrink)

Recently, in increasing numbers, citizens of wealthy nations are heading to poorer countries for medical care. They are traveling to the global South as medical tourists because in their home nations either they cannot get timely medical care or they cannot afford needed treatments. This essay offers a robust, particularist ethical assessment of the practice of citizens of richer nations traveling to poorer countries for healthcare.

Aiming at the suspension cable system of an unmanned helicopter with sensor fault under complex environment, this paper studies the robust antiswing tolerant control scheme. To suppress the swing of the hanging load when the unmanned helicopter is in the forward flight state, a nonlinear line motion model is firstly established. Considering the sensor fault of the unmanned helicopter, a sensor fault estimator is developed. By using the fault estimator output, the robust antiswing tolerant controller is proposed using the backstepping (...) technique and sliding mode control method. Under the designed robust antiswing tolerant controller, the desired tracking control performance can be obtained and the swing angle of the load is guaranteed small under the sensor fault. Furthermore, the closed-loop system stability is analyzed by using the Lyapunov technique. Simulation studies are given to show the efficiency of the designed robust antiswing control strategy. (shrink)

Modelers often rely on robustness analysis, the search for predictions common to several independent models. Robustness analysis has been characterized and championed by Richard Levins and William Wimsatt, who see it as central to modern theoretical practice. The practice has also been severely criticized by Steven Orzack and Elliott Sober, who claim that it is a nonempirical form of confirmation, effective only under unusual circumstances. This paper addresses Orzack and Sober's criticisms by giving a new account of (...) class='Hi'>robustness analysis and showing how the practice can identify robust theorems. Once the structure of robust theorems is clearly articulated, it can be shown that such theorems have a degree of confirmation, despite the lack of direct empirical evidence for their truth. (shrink)

Scientific research is almost always conducted by communities of scientists of varying size and complexity. Such communities are effective, in part, because they divide their cognitive labor: not every scientist works on the same project. Philip Kitcher and Michael Strevens have pioneered efforts to understand this division of cognitive labor by proposing models of how scientists make decisions about which project to work on. For such models to be useful, they must be simple enough for us to understand their dynamics, (...) but faithful enough to reality that we can use them to analyze real scientific communities. To satisfy the first requirement, we must employ idealizations to simplify the model. The second requirement demands that these idealizations not be so extreme that we lose the ability to describe real-world phenomena. This paper investigates the status of the assumptions that Kitcher and Strevens make in their models, by first inquiring whether they are reasonable representations of reality, and then by checking the models' robustness against weakenings of these assumptions. To do this, we first argue against the reality of the assumptions, and then develop a series of agent-based simulations to systematically test their effects on model outcomes. We find that the models are not robust against weakenings of these idealizations. In fact we find that under certain conditions, this can lead to the model predicting outcomes that are qualitatively opposite of the original model outcomes. (shrink)

Living systems employ several mechanisms and behaviors to achieve robustness and maintain themselves under changing internal and external conditions. Regulation stands out from them as a specific form of higher-order control, exerted over the basic regime responsible for the production and maintenance of the organism, and provides the system with the capacity to act on its own constitutive dynamics. It consists in the capability to selectively shift between different available regimes of self-production and self-maintenance in response to specific signals (...) and perturbations, due to the action of a dedicated subsystem which is operationally distinct from the regulated ones. The role of regulation, however, is not exhausted by its contribution to maintain a living system’s viability. While enhancing robustness, regulatory mechanisms play a fundamental role in the realization of an autonomous biological organization. Specifically, they are at the basis of the remarkable integration of biological systems, insofar as they coordinate and modulate the activity of distinct functional subsystems. Moreover, by implementing complex and hierarchically organized control architectures, they allow for an increase in structural and organizational complexity while minimizing fragility. Finally, they endow living systems, from their most basic unicellular instances, with the capability to control their own internal dynamics to adaptively respond to specific features of their interaction with the environment, thus providing the basis for the emergence of minimal forms of cognition. (shrink)