Hybrid Views Research Articles

Hybrid expressivism and epistemic justification

Epistemic expressivists maintain, to a first approximation, that epistemic assertions express non-cognitive mental states, like endorsements, valuations, or pro-attitudes, rather than cognitive mental states such as beliefs. Proponents of epistemic expressivism include Chrisman (Philos Stud 135: 225–254, 2007), Gibbard (Wise choices, apt feelings, 1990, Thinking how to live, 2003), Field (Proc Aristot Soc 96:359–379, 1996, Philos Stud 92:1–24, 1998, Philos Stud 143:249–290, 2009), Kappel (Acta Anal 25:175–194, 2010), and Ridge (Proc Aristot Soc 81:83–108, 2007a), among others. In this paper, I argue for an alternative view to epistemic expressivism. The view I seek to advocate is inspired by hybrid expressivist theories about moral judgments (see e.g. Barker (Analysis 60:268–279, 2000), Copp (Soc Philos Policy 18:1–43, 2001, in: Shafer-Landau (ed.) Oxford studies in metaethics, 2009), Finlay (J Ethics 8:205–223, 2004, Philos Impr 5:1–20, 2005), Strandberg (Philos Phenomenol Res 84:87–120, 2012)). According to these hybrid views, moral judgments express semantically cognitive or representational states and pragmatically convey the speaker’s non-cognitive mental states via implicatures. I will argue that a particular version of this view can reasonably be extended to epistemic judgments and that it has several advantages over its expressivist and cognitivist competitors. In particular, I will try to show that there exist certain phenomena in the epistemic domain that seem to be best accounted for by expressivist theories of epistemic judgments. However, a version of hybrid expressivism that maintains that epistemic judgments convey the attributor’s non-cognitive mental states via generalized conversational implicatures is able to account for these phenomena just as well without running afoul of the main problems that have been identified for different versions of epistemic expressivism.

Concepts as Pluralistic Hybrids

In contrast to earlier views that argued for a particular kind of concept (e.g. prototypes), several recent accounts have proposed that there are multiple distinct kinds of concepts, or that there is a plurality of concepts for each category. In this paper, I argue for a novel account of concepts as pluralistic hybrids. According to this view, concepts are pluralistic because there are several concepts for the same category whose use is heavily determined by context. In addition, concepts are hybrids because they typically link together several different kinds of information that are used in the same cognitive processes. This alternative view accounts for the available empirical data, allows for greater cognitive flexibility than Machery's recent account, and overcomes several objections to traditional hybrid views.

Options for Hybrid Expressivism

In contemporary metaethics, various versions of hybrid expressivism have been proposed according to which moral sentences express both non-cognitive attitudes and beliefs. One important advantage with such positions, its proponents argue, is that they, in contrast to pure expressivism, have a straightforward way of avoiding the Frege-Geach problem. In this paper, I provide a systematic examination of different versions of hybrid expressivism with particular regard to how they are assumed to evade this problem. The major conclusion is that none of these views succeeds to provide both a fully satisfying interpretation of moral sentences and a convincing response to the Frege-Geach problem. I end by briefly considering alternative hybrid views that employ the notion of conventional or conversational implicature.

Swi2/Snf2 remodelers: hybrid views on hybrid molecular machines

Swi2/Snf2 (switch/sucrose non-fermentable) enzymes form a large and diverse class of proteins and multiprotein assemblies that remodel nucleic acid:protein complexes, using the energy of ATP hydrolysis. The core Swi2/Snf2 type ATPase domain belongs to the 'helicase and NTP driven nucleic acid translocase' superfamily 2 (SF2). It serves as a motor that functionally and structurally interacts with different targeting domains and functional modules to drive a plethora of remodeling activities in chromatin structure and dynamics, transcription regulation and DNA repair. Recent progress on the interaction of Swi2/Snf2 enzymes and multiprotein assemblies with their substrate nucleic acids and proteins, using hybrid structural biology methods, illuminates mechanisms for complex chemo-mechanical remodeling reactions. For Mot1, a hybrid mechanism of remodeler and chaperone emerged.

Real time UAV altitude, attitude and motion estimation from hybrid stereovision

Knowledge of altitude, attitude and motion is essential for an Unmanned Aerial Vehicle during critical maneuvers such as landing and take-off. In this paper we present a hybrid stereoscopic rig composed of a fisheye and a perspective camera for vision-based navigation. In contrast to classical stereoscopic systems based on feature matching, we propose methods which avoid matching between hybrid views. A plane-sweeping approach is proposed for estimating altitude and detecting the ground plane. Rotation and translation are then estimated by decoupling: the fisheye camera contributes to evaluating attitude, while the perspective camera contributes to estimating the scale of the translation. The motion can be estimated robustly at the scale, thanks to the knowledge of the altitude. We propose a robust, real-time, accurate, exclusively vision-based approach with an embedded C++ implementation. Although this approach removes the need for any non-visual sensors, it can also be coupled with an Inertial Measurement Unit.

Hybrid Deterministic Views About Genes in Biology Textbooks: A Key Problem in Genetics Teaching

A major source of difficulties in promoting students’ understanding of genetics lies in the presentation of gene concepts and models in an inconsistent and largely ahistorical manner, merely amalgamated in hybrid views, as if they constituted linear developments, instead of being built for different purposes and employed in specific contexts. In this paper, we report the results of a study about how textbooks can provide the grounds for the students’ construction of such hybrid views about genes. These views are a key problem in genetics teaching, because they make it more difficult that students properly understand this central biological concept and strengthen genetic deterministic ideas, which characterize a widespread discourse about genes in the public opinion. We analyzed 18 textbooks using categorical content analysis, employing categories derived from the literature addressing the historical development of gene models and concepts. Our findings indicate that the analyzed textbooks do convey hybrid views about genes, with no correspondence to scientific models related to this biological concept. These views reinforce genetic deterministic discourses and may lead students to serious misunderstandings about the nature of genes and their role in living systems, with consequences to future learning about genetics.

On model checking multiple hybrid views

Many applications, for instance the MS .NET Global Assembly Cache (GAC), are naturally expressed as 3-valued models where an additional third truth value models uncertainty or under-specification. An example of under-specification is that a component in a GAC may or may not have a main method. Models described in this manner can then be analyzed to refute or verify properties about the concrete systems they intend to model. This approach to system validation traditionally considers only one model at a time, even though this model may evolve if subjected to analysis. Many applications, however, benefit from or require the simultaneous consideration of multiple models of systems. We mention here requirements from different stake holders, and data drawn from federated databases. This paper therefore builds the mathematical foundations for property verification and refutation as applied to finitely many 3-valued models, where each model is endowed with states — possibly named by nominals, also known as hybrid constraints — labelled transitions, and atomic propositions. Specifically, we show that deciding whether a finite set of models has a common concrete system (consistency) is typically in PTIME, and that deciding whether a common concrete system satisfies a formula of the hybrid mu-calculus (satisfiability), and its dual (validity), are EXPTIME-complete. We propose sound and efficient approximations of these EXPTIME-complete checks by synthesizing and checking “summary” models. These approximations are optimal if all models are deterministic. Finally, we point out that such optimality of summary models is unattainable whenever not all summarized models are deterministic.

Tower of Babel: Variation in Ethical Approaches, Concepts of Welfare and Attitudes to Genetic Manipulation

Attitudes to animal biotechnology are diverse, partly because people have different viewpoints and often do not recognize or acknowledge this to be so. First, people adopt different ethical approaches. If an opponent of genetic manipulation says 'I don't like the idea of altering animals' biology' and a proponent replies '...but it is useful', they are failing to communicate, because one is asking whether the action is right or wrong, whereas the other emphasizes the consequences. Another approach focuses on the person carrying out the action. Many people have hybrid views combining elements of these different approaches. Second, people's concepts of welfare vary, emphasizing animal minds, bodies or natures--or a combination of these. A proponent who argues that a particular genetic change will not cause suffering is unlikely to reassure an opponent who puts more emphasis on naturalness than on feelings or health. An improved dialogue, in which people attempt to understand one another's viewpoints, may enable common principles to be established and practical measures to be taken that enable more cooperation in attempts to improve both human and animal welfare.

Prerogatives Without Restrictions

Consequentialists hold that the right act in any situation is the one that will produce the best overall outcome, as judged from an impersonal point of view. By contrast, many non-consequentialists maintain that, given any impersonal principle for ranking overall outcomes from best to worst, there will be some circumstances in which one is forbidden to produce the best available outcome so characterized, and still others in which one is permitted but not required to do so. They accept, in other words, both what I call agentcentered restrictions and what I call an agent-centered prerogative.1 In The Rejection of Consequentialism,2 I argued that an agent-centered prerogative is easier to explain and defend than are agent-centered restrictions For, I suggested, whereas it is possible to identify an underlying principled rationale for such a prerogative, a comparable rationale for agentcentered restrictions is surprisingly elusive In consequence, I argued, theories, which depart from consequentialism to the extent of incorporating an agent-centered prerogative, but which do not include agent-centered restrictions, deserve our attention. In the ensuing discussion, a number of writers have argued that hybrid theories have radically counterintuitive implications and cannot be accepted. However, these writers have disagreed among themselves about what conclusion to draw from this. Some have seen the criticism of such theories as helping to vindicate a version of commonsense morality, which is taken to include both prerogatives and restrictions, while others have treated the criticism as casting doubt on the advisability of any departure from consequentialism. The former, in effect, see the alleged defects of hybrid views as helping to supply the missing rationale for agent-centered restrictions. The latter regard the indefensibility of the restrictions as a fixed point, and treat the supposed unacceptability of hybrid views as serving to eliminate another potential rival to consequentialism. In this paper, I will explore the force and significance of some of the objections that generate these divergent responses.