The evolution of a variety of important chromophore‐dependent biological processes, including microbial light sensing and mammalian color vision, relies on protein modifications that alter the spectral characteristics of a bound chromophore. Three different color opsins share the same chromophore, but have three distinct absorptions that together cover the entire visible spectrum, giving rise to trichromatic vision. The influence of opsins on the absorbance of the chromophore has been studied through methods such as model compounds, opsin mutagenesis, and computational modeling. The (...) recent development of rhodopsin mimic that uses small soluble proteins to recapitulate the binding and wavelength tuning of the native opsins provides a new platform for studying protein‐regulated spectral tuning. The ability to achieve far‐red shifted absorption in the rhodopsin mimic system was attributed to a combination of the lack of a counteranion proximal to the iminium, and a uniformly neutral electrostatic environment surrounding the chromophore. (shrink)

Rhodopsin, upon activation by light, transduces the photon signal by activation of the G‐protein, transducin. The well‐studied rhodopsin/transducin system serves as a model for the understanding of signal transduction by the large class of G‐protein‐coupled receptors. The interactive form of rhodopsin, R*, is conformationally similar or identical to rhodopsin's photolysis intermediate Metarhodopsin II (MII). Formation of MII requires deprotonation of rhodopsin's protonated Schiff base which appears to facilitate some opening of the rhodopsin structure. This (...) allows a change in conformation at rhodopsin's cytoplasmic surface that provides binding sites for transducin. Rhodopsin's 2nd, 3rd and putative 4th cytoplasmic loops bind transducin at sites including transducin's 5 kDa carboxyl‐terminal region. Site‐specific mutagenesis of rhodopsin is being used to distinguish sites on rhodopsin's surface that are important in binding transducin from those that function in activating transducin. These observations are consistent with and extend studies on the action of other G‐protein‐coupled receptors and their interactions with their respective G proteins. (shrink)

The structure of rhodopsin is a subject of intense interest. Solving the structure by traditional methods has proved exceedingly challenging. It may therefore be useful to confront the problem by a combination of alternate techniques. These include FTIR (Fourier transform infrared spectroscopy) and AFM (atomic force microscopy) on the intact protein. Furthermore, additional insights may be gained through structural investigations of discrete rhodopsin domains.

Light activated rhodopsin functions by catalyzing the exchange of GTP for GDP on numerous copies of transducin. Peptide mapping has shown that at least six regions, three on rhodopsin and three on the transducin alpha subunit, are involved in the active interface between the two proteins. The most informative structural studies of rhodopsin should include focus on the transducin interaction.

Rapidly advancing studies on rhodopsin have focused on new strategies for crystallization of this integral membrane protein for x-ray analysis and on alternative methods for structural determination from nuclear magnetic resonance data. Functional studies of the interactions between the apoprotein and its chromophore have clarified the role of the chromophore in deactivation of opsin and in photoactivation of the pigment.

This study discusses the mimic octopus’ acts of imitation of a banded sea-snake as an antagonistic response to enemies from a cognitive-semiotic perspective. This mimicry model, which involves very close physical resemblance and highly precise enactment, displays goal-orientedness because the octopus only takes it on when encountering damselfish, a territorial species, and not other sea animals that the octopus has been shown to imitate, such as lionfish and flounders. Based on theoretical principles and analytic tools from Mitchell’s typology of (...) deceptive acts, Zlatev’s Mimesis Hierarchy and Zlatev’s types and levels of consciousness, this research raises the possibility that T. mimicus exhibits the following attributes: bodily self-awareness; cognitive empathy, which builds upon deception and perspective-taking strategies to imagine or project itself into the place of the antagonist; and capability to reflectively reorganise the standard complete imitation pattern into a partial one in order to optimise its effect, based on conscious visual appraisal of the stimulus position. These capacities would place T. mimicus at the dyadic mimetic level on the Mimesis Hierarchy. For this reason, it is suggested that the name mimic octopus could be replaced by mimetic octopus. (shrink)

To understand how the photoreceptor protein rhodopsin performs in its role as a receptor, its structure needs to be determined at the atomic level. Upon receiving a photon of light, rhodopsin undergoes a change in conformation that allows it to bind and activate the C-protein, transducin. An important future goal should be to determine the structure of both the inactive and the photoactivated state of rhodopsin, R*. This should provide the groundwork necessary for experiments on how (...) class='Hi'>rhodopsin achieves its signaling state R*, and how R* functions to activate transducin. To do this, the crystal structure of both rhodopsin and R* must be determined. Few membrane proteins have been successfully crystallized, so this is not a trivial undertaking. Two- or three dimensional crystals of rhodopsin must be prepared that are well ordered, to produce a high-resolution structure. Rhodopsin must be purified to homogeneity and the appropriate detergent(s) selected for crystallization experiments. Long-term thermal stability of the rhodopsin-detergent complex must be achieved in the presence of a precipitant. Two-dimensional crystals may offer advantages in investigating the structure of R*, but the structure obtained may be limited in resolution. It is necessary to work with rhodopsin in the dark, unless suitable light-stable retinal derivatives are developed. Protein engineering of rhodopsin offers attractive opportunities to improve its ability to crystallize, but is presently hindered by the absence of a high-yielding expression system. Knowledge of the structure of rhodopsin will have general importance. Because rhodopsin is a member of the family of C-protein-coupled receptors, knowledge of the structure and the mechanism of action of rhodopsin suggests by analogy how other members of the receptor family may function. (shrink)

This study discusses the mimic octopus’ (Thaumoctopus mimicus) acts of imitation of a banded sea-snake (Laticauda sp.) as an antagonistic response to enemies from a cognitive-semiotic perspective. This mimicry model, which involves very close physical resemblance and highly precise enactment, displays goal-orientedness because the octopus only takes it on when encountering damselfish, a territorial species, and not other sea animals that the octopus has been shown to imitate, such as lionfish and flounders (Norman et al. 2001). Based on theoretical (...) principles and analytic tools from Mitchell’s (1986) typology of deceptive acts, Zlatev’s (2008) Mimesis Hierarchy and Zlatev’s (2018) types and levels of (self-)consciousness, this research raises the possibility that T. mimicus exhibits the following attributes: (i) bodily self-awareness; (ii) cognitive empathy, which builds upon deception and perspective-taking strategies to imagine or project itself into the place of the antagonist; and (iii) capability to reflectively reorganise the standard complete imitation pattern into a partial one in order to optimise its effect, based on conscious visual appraisal of the stimulus position. These capacities would place T. mimicus at the dyadic mimetic level on the Mimesis Hierarchy. For this reason, it is suggested that the name mimic octopus could be replaced by mimetic octopus. (shrink)

I argue for the existence of intrinsic Finks, Masks, and Mimics, and argue that these undermine certain recent attempts to revive simple conditional analyses of dispositions. I present some examples of intrinsic Finks, Masks, and Mimics, and argue that the example of an intrinsic fink I present has certain advantages over the examples of intrinsic finks recently suggested by Randolph Clarke. I conclude that the existence of such Finks, Masks, and Mimics, undermine a recent attempt by Sungho Choi to distinguish (...) dispositional properties from categorical properties. (shrink)

Rhodopsins are one of the most studied photoreceptor protein families, and ion‐translocating rhodopsins, both pumps and channels, have recently attracted broad attention because of the development of optogenetics. Recently, a new functional class of ion‐pumping rhodopsins, an outward Na+ pump, was discovered, and following structural and functional studies enable us to compare three functionally different ion‐pumping rhodopsins: outward proton pump, inward Cl− pump, and outward Na+ pump. Here, we review the current knowledge on structure‐function relationships in these three light‐driven pumps, (...) mainly focusing on Na+ pumps. A structural and functional comparison reveals both unique and conserved features of these ion pumps, and enhances our understanding about how the structurally similar microbial rhodopsins acquired such diverse functions. We also discuss some unresolved questions and future perspectives in research of ion‐pumping rhodopsins, including optogenetics application and engineering of novel rhodopsins. (shrink)

NMR (nuclear magnetic resonance) may be useful for determining the structure of retinal and its environment in rhodopsin, but not for determining the complete protein structure. Aggregation and low yield of fragments of rhodopsin may make them difficult to study by NMR. A long-term multidisciplinary attack on rhodopsin structure is required.

The photocycle of visual opsins is essential to maintain the light sensitivity of the retina. The early physical observations of the rhodopsin photocycle by Böll and Kühne in the 1870s inspired over a century's worth of investigations on rhodopsin biochemistry. A single photon isomerizes the Schiff‐base linked 11‐cis‐retinylidene chromophore of rhodopsin, converting it to the all‐trans agonist to elicit phototransduction through photoactivated rhodopsin (Rho*). Schiff base hydrolysis of the agonist is a key step in the photocycle, (...) not only diminishing ongoing phototransduction but also allowing for entry and binding of fresh 11‐cis chromophore to regenerate the rhodopsin pigment and maintain light sensitivity. Many challenges have been encountered in measuring the rate of this hydrolysis, but recent advancements have facilitated studies of the hydrolysis within the native membrane environment of rhodopsin. These techniques can now be applied to study hydrolysis of agonist in other opsin proteins that mediate phototransduction or chromophore turnover. In this review, we discuss the progress that has been made in characterizing the rhodopsin photocycle and the journey to characterize the hydrolysis of its all‐trans‐retinylidene agonist. (shrink)

In the context of 1960s research on biological membranes, scientists stumbled upon a curiously coloured material substance, which became called the “purple membrane.” Interactions with the material as well as chemical analyses led to the conclusion that the microbial membrane contained a photoactive molecule similar to rhodopsin, the light receptor of animals’ retinae. Until 1975, the find led to the formation of novel objects in science, and subsequently to the development of a field in the molecular life sciences that (...) comprised biophysics, bioenergetics as well as membrane and structural biology. Furthermore, the purple membrane and bacteriorhodopsin, as the photoactive membrane transport protein was baptized, inspired attempts at hybrid bio-optical engineering throughout the 1980s. A central motif of the research field was the identification of a functional biological structure, such as a membrane, with a reactive material substance that could be easily prepared and manipulated. Building on this premise, early purple membrane research will be taken as a case in point to understand the appearance and transformation of objects in science through work with material substances. Here, the role played by a perceptible material and its spontaneous change of colour, or reactivity, casts a different light on objects and experimental practices in the late twentieth century molecular life sciences. With respect to the impact of chemical working and thinking, the purple membrane and rhodopsins represent an influential domain straddling the life and chemical sciences as well as bio- and material technologies, which has received only little historical and philosophical attention. Re-drawing the boundary between the living and the non-enlivened, these researches explain and model organismic activity through the reactivity of macromolecular structures, and thus palpable material substances. (shrink)

Why do irrational beliefs adopt the trappings of science, to become what is known as “pseudoscience”? Here, we develop and extend an epidemiological framework to map the factors that explain the form and the popularity of irrational beliefs in scientific garb. These factors include the exploitation of epistemic vigilance, the misunderstanding of the authority of science, the use of the honorific title of “science” as an explicit argument for belief, and the phenomenon of epistemic negligence. We conclude by integrating the (...) various factors in an epidemiological framework and thus provide a comprehensive cultural evolutionary account of science mimicry. (shrink)

Why do irrational beliefs adopt the trappings of science, to become what is known as “pseudoscience”? Here, we develop and extend an epidemiological framework to map the factors that explain the form and the popularity of irrational beliefs in scientific garb. These factors include the exploitation of epistemic vigilance, the misunderstanding of the authority of science, the use of the honorific title of “science” as an explicit argument for belief, and the phenomenon of epistemic negligence. We conclude by integrating the (...) various factors in an epidemiological framework and thus provide a comprehensive cultural evolutionary account of science mimicry. (shrink)

This article explores interpersonal functions of emotional mimicry under the absence versus the presence of visual contact between the interacting partners. We review relevant literature and stress that previous studies on the role of emotional mimicry were focused on imitative responses to facial displays. We also show that the rules explaining why people mimic facial expressions may be inapplicable when visual signals are unavailable (e.g., people attending an online meeting have their cameras off). Overall, our review suggests that emotional (...) mimicry functionally adapts to whether the perceiver and the expresser can see each other. We, therefore, argue that blocking visual contact between them may provide insight into emotional mimicry's social functions, thereby clarifying its role in fostering affiliation and emotional understanding. (shrink)

A class of maize mutants, collectively known as disease lesion mimics, display discrete disease‐like symptoms in the absence of pathogens. It is intriguing that a majority of these lesion mimics behave as dominant gain‐of‐function mutations. The production of lesions is strongly influenced by light, temperature, developmental state and genetic background. Presently, the biological significance of this lesion mimicry is not clear, although suggestions have been made that they may represent defects in the plants' recognition of, or response to, pathogens. One (...) feature that is common to all lesion mimics is their association with cell death. In plants, as in animals, a number of developmental and pathological processes exist where controlled cell death, whether programmed or triggered in response to physiological or environmental stimuli, constitutes the normal aspect of life. Might disease lesion mimic mutations represent variants where regulation of desirable cell death has gone awry? In this paper we argue that this might be the case, and further conjecture that these mutants offer a unique opportunity for studying the genetic and cellular mechanisms of cell death in plants. (shrink)

Strong arguments are presented by Hargrave suggesting that the crystallization of visual rhodopsin for high resolution analysis by X-ray crystallography or electron microscopy is feasible. However, the effort needed to achieve this goal will most likely exceed the resources of a single laboratory and a concerted approach to the research is necessary.

Magic angle spinning (MAS) NMR methods provide a means of obtaining high resolution structural data on rhodopsin and its photoin termediates. Current work has focused on the structure of the retinal chromophore and its interactions with surrounding protein charges. The recent development of MAS NMR methods for measuring internuclear distances with a resolution of ∼0.2 will complement diffraction methods for addressing key mechanistic questions.

In the current model of visual transduction, the lifetime of active cGMP phosphodiesterase depends upon the period of its interaction with GTP-bound transducin. If recoverin regulates the lifetime of light-activated cGMP phosphodiesterase through inhibition of rhodopsin phosphorylation, rhodopsin should directly interact with cGMP phosphodiesterase and/or GTP-bound transducin complexed with cGMP phosphodiesterase. Is this true?

This thesis presents an alternative method for the detection of MIMIC models. Previous methods (such as factor analysis) suffer from a number of significant aws and limitations, which the new method (a causal search algorithm) doesn't suffer. A new algorithm is introduced, followed by a worked-through example of its application. Discussion focuses on some of the limiting assumptions the algorithm currently requires. Finally, recommendations for future work address improvements of the algorithm, as well as its applicability.

This commentator has no argument with the explanations given by Soltis. Yet a different approach to the phenomenon of crying might be fruitful. Neonates elicit care. It is hypothesized that non-neonates evolved to mimic, when in need, the appearance of the neonate by crying and by shedding tears, thus inducing helping behavior by the spectator.

In an effort to produce new and more sustainable technologies, designers have turned to nature in search of inspiration and innovation. Biomimetic design (from the Greek bios, life, mimesis, imitation) is the conscious imitation of biological models to solve today's technical and ecological challenges. Nowadays numerous different approaches exist that take inspiration from nature as a model for design, such as biomimicry, biomimetics, bionics, permaculture, ecological engineering, etc. This variety of practices comes in turn with a wide range of different (...) promises, including sustainability, increased resilience, multi-functionality, and a lower degree of risk. How are we to make sense of this heterogeneous amalgam of existing practices and technologies, and of the numerous promises attached to them? We suggest that a typology of biomimetic approaches would provide a useful hermeneutic framework to understand the different tensions that pull this variegated landscape in different directions. This is achieved through a critical analysis of the literature in different fields of biomimetic design and the philosophy of biomimicry, in order to derive conceptual and normative assumptions concerning the meaning and value of the imitation of nature. These two dimensions are then intersected to derive an analytical grid composed of six different biomimetic types, which enable the classification of existing and possible biomimetic approaches, practices, and technologies according to their specific conceptual assumptions and guiding norms. (shrink)

Facial electromyography (EMG) was used to investigate patterns of facial mimicry in response to partial facial expressions in two contexts that differ in how naturalistic and socially significant the faces are. Experiment 1 presented participants with either the upper- or lower-half of facial expressions and used a forced-choice emotion categorisation task. This task emphasises cognition at the expense of ecological and social validity. Experiment 2 presented whole heads and expressions were occluded by clothing. Additionally, the emotion recognition task is more (...) open-ended. This context has greater social validity. We found mimicry in both experiments, however mimicry differed in terms of which emotions were mimicked and the extent to which the mimicry involved muscle sites that were not observed. In the more cognitive context, there was relatively more motor matching (i.e. mimicking only what was seen). In the more socially valid context, participants were less likely to mimic only what they saw – and instead mimicked what they knew. Additionally, participants mimicked anger in the cognitive context but not the social context. These findings suggest that mimicry involves multiple mechanisms and that the more social the context, the more likely it is to reflect a mechanism of social regulation. (shrink)

This commentary considers the typology and conceptual and normative heuristic framework as proposed by the authors as a valuable contribution to the new field of philosophy of biomimetics and to the growing demand for critical evaluation of technology and design (decisions) in terms of ecological sustainability. However, further steps are needed to develop a more comprehensive normative analysis and evaluation. To inspire these efforts, I outline some additional normative dimensions of what I propose to call the ‘eco-normative profiling’ of technologies (...) and design. (shrink)

Research indicates that emotional mimicry predominantly occurs in response to affiliative displays, such as happiness, while the mimicry of antagonistic displays, like anger, is seldom observed in social contexts. However, contextual factors, including the identity of the displayer (e.g. social similarity with the observer) and whose action triggered the emotional reaction (i.e. to whom display is directed), can modulate the meaning of the display. In two experiments, participants observed happiness, sadness, and anger expressed by individuals with similar or different social (...) attitudes in response to actions from either a participant or another person. Results demonstrated that three manipulated factors – displayer social similarity, whose action caused an emotional display, and the type of emotional display – affected participants’ perception of the display. In turn, mimicry was predominantly observed in response to happiness (Experiments 1 and 2), to a lesser extent to sadness (Experiment 1), and not to anger. Furthermore, participants mimicked individuals who were more socially similar (Experiment 1), while whose action caused an emotional reaction did not influence mimicry. The findings suggest that when the context mitigates the meaning of negative or antagonistic facial displays, it does not necessarily increase the inclination to mimic them. (shrink)

Sexually active male haplochromine cichlid fishes possess pronounced yellow ovoid spots on the anal fm, which mimic eggs of the female and have therefore been called egg dummies (Wickler, 1962b).It is thought that divergence in egg dummy characteristics can considerably reduce gene flow and in this way may trigger off reproductive isolation. Two ways in which egg dummy divergence can develop are described. Both mechanisms may have been operating, at the same time and in the same area, in different (...) species, or possibly even in a single species. (shrink)

Tissue plasminogen activator (tPA) is administered to patients with suspected ischemic stroke to improve blood flow to the brain In rare cases, patients present with complaints of stroke symptoms that appear to be non-organic due to malingering, factitious disorder, or conversion disorder (psychogenic stroke mimics). Deciding whether or not to administer tPA to these patients can be challenging. The risk of hemorrhage after administration of tPA is low, but not zero. The ethical principles of beneficence and nonmaleficence need to be (...) weighed carefully in these situations. We present two cases of patients with suspected psychogenic stroke mimics to illustrate the ethical challenges faced in identifying and managing psychogenic stroke mimics. Further research is needed to demonstrate effective treatment strategies for patients with acute stroke symptoms of psychogenic etiology. (shrink)

Children approach counterfactual questions about stories with a reasoning strategy that falls short of adults’ Counterfactual Reasoning (CFR). It was dubbed “Basic Conditional Reasoning” (BCR) in Rafetseder et al. (Child Dev 81(1):376–389, 2010). In this paper we provide a characterisation of the differences between BCR and CFR using a distinction between permanent and nonpermanent features of stories and Lewis/Stalnaker counterfactual logic. The critical difference pertains to how consistency between a story and a conditional antecedent incompatible with a nonpermanent feature of (...) the story is achieved. Basic conditional reasoners simply drop all nonpermanent features of the story. Counterfactual reasoners preserve as much of the story as possible while accommodating the antecedent. (shrink)

Severe COVID‐19 is often accompanied by coagulopathies such as thrombocytopenia and abnormal clotting. Rarely, such complications follow SARS‐CoV‐2 vaccination. The cause of these coagulopathies is unknown. It is hypothesized that coagulopathies accompanying SARS‐CoV‐2 infections and vaccinations result from bacterial co‐infections that synergize with virus‐induced autoimmunity due to antigenic mimicry of blood proteins by both bacterial and viral antigens. Coagulopathies occur mainly in severe COVID‐19 characterized by bacterial co‐infections with Streptococci, Staphylococci, Klebsiella, Escherichia coli, and Acinetobacter baumannii. These bacteria express unusually (...) large numbers of antigens mimicking human blood antigens, as do both SARS‐CoV‐2 and adenoviruses. Bacteria mimic cardiolipin, prothrombin, albumin, and platelet factor 4 (PF4). SARS‐CoV‐2 mimics complement factors, Rh antigens, platelet phosphodiesterases, Factors IX and X, von Willebrand Factor (VWF), and VWF protease ADAMTS13. Adenoviruses mimic prothrombin and platelet factor 4. Bacterial prophylaxis, avoidance of vaccinating bacterially infected individuals, and antigen deletion for vaccines may reduce coagulopathy risk. Also see the video abstract here: https://youtu.be/zWDOsghrPg8. (shrink)

Diseases causing inherited retinal degeneration in humans, such as retinitis pigmentosa and macular dystrophy, are genetically heterogeneous and clinically diverse. More than 40 genes causing retinal degeneration have been mapped to specific chromosomal sites; of these, at least 10 have been cloned and characterized. Mutations in two proteins, rhodopsin and peripherin/RDS, account for approximately 35% of all cases of autosomal dominant retinitis pigmentosa and a lesser fraction of other retinal conditions. This target article reviews the genes and mutations causing (...) retinal degeneration and proposes mechanisms whereby specific mutations lead to particular clinical consequences, that is, the relationship between genotype and phenotype. Retinitis pigmentosa and macular dystrophy are genetically heterogeneous diseases that cause retinal degeneration in humans and often result in severe visual impairment or blindness. Although many of the genes causing these diseases have not been identified, three photoreceptor-specific proteins have been implicated: rhodopsin, peripherin/RDS, and the P-subunit of rod phosphodiesterase. Mutations in the genes for these three proteins can cause either dominant retinitis pigmentosa, recessive retinitis pigmentosa, dominant congenital stationary night blindness, or dominant macular degeneration. Why this multiplicity of clinical phenotypes? Our target article summarizes the genetic and biochemical background to this question and proposes a number of possible explanations. Discussion focuses mainly on 73 distinct disease-causing mutations of rhodopsin. We feel that rhodopsin and other photoreceptor proteins can serve as model systems for unraveling the connection between genotype and phenotype, not only for inherited retinal diseases but for other degenerative disorders as well. (shrink)

Computers can mimic human intelligence, sometimes quite impressively. This has led some to claim that, a.) computers can actually acquire intelligence, and/or, b.) the human mind may be thought of as a very sophisticated computer. In this paper I argue that neither of these inferences are sound. The human mind and computers, I argue, operate on radically different principles.

This book argues that a conscientiously objecting medical professional should receive an exemption only if the grounds of an objector's refusal are reasonable. It defends a detailed, contextual account of public reasonability suited for healthcare, which builds from the overarching concept of Rawlsian public reason. The author analyzes the main competing positions and maintains that these other views fail precisely due to their systematic inattention to the grounding reasons behind a conscientious objection; he argues that any such view is plausible (...) to the extent that it mimics the 'reason-giving requirement' for conscience objections defended in this work. Only reasonable objections can defeat the prior professional obligation to assign primacy to patient well-being, therefore one who refuses a patient's request for a legally available, medically indicated, and safe service must be able to explain the grounds of their objection in terms understandable to other citizens within the public institutional structure of medicine. The book further offers a novel policy proposal to deploy the Reasonability View: establishing conscientious objector status in medicine. It concludes that the Reasonability View is a viable and attractive position in this debate. A New Theory of Conscientious Objection in Medicine: Justification and Reasonability will be of interest to researchers and advanced students working in bioethics, medical ethics, and philosophy of medicine, as well as thinkers interested in the intersections between law, medical humanities, and philosophy. (shrink)

How should we understand the emotional rationality? This first part will explore two models of cognition and analogy strategies, test their intuition about the emotional desire. I distinguish between subjective and objective desire, then presents with a feeling from the "paradigm of drama" export semantics, here our emotional repertoire is acquired all the learned, and our emotions in the form of an object is fixed. It is pretty well in line with the general principles of rationality, especially the lowest reasonable (...) principles. Turned to the second part of this side of reasonable. I will inquire how emotional beliefs, desires, and behaviors contribute to the rationality. I will present a very general biological hypothesis: emotions by controlling highlights the characteristics of perception and reasoning, so that we remove the difficulties due in particular to lead to paralysis; they are being simulated by a simplified perception of information, thus limiting our practice and cognitive choice. How are we to understand emotional or axiological rationality? I pursue analogies with both the cognitive and the strategic models, testing them against intuitions about emotional desires. We distinguish two different classes of desires, the subjective and the objective, and propose that emotions have a semantics that derives from "paradigmatic scenarios", in terms of which our emotional repertoire is learned and the formal objects of our emotions fixed. This fits in well with emerging facts about how our emotional capacities develop, and it can also be squared with the general principles of rationality, particularly minimal rationality. In the second part, I return to the perspective of rationality. I ask how emotions contribute to the rationality of beliefs, desires, and behavior. I proffer a very general biological hypothesis: Emotions spare us the paralysis potentially induced by a particular predicament by controlling the salience of features of perception and reasoning; they temporarily mimic the informational encapsulation of perception and so circumscribe our practical and cognitive options. (shrink)

Ontic Structural Realism (OSR) gives ontic priority to structures over objects. In its perhaps most extreme form (captured, admittedly, by a slogan) it states that “all that there is, is structure” (da Costa and French 2003, 189). If this is true, if there is nothing but structure(s) in the world, the very idea of contrasting structure to nonstructure loses any force it might have. Actually, if the slogan is right, the very idea of characterising what there is as structure—as opposed (...) to anything else—becomes incoherent. Traditionally, characterising something as a structure has made full sense —and has served excellent scientific and philosophical purposes—precisely because structure was understood as an entity with slots, which could be occupied by objects and whose individuation-conditions involved objects only qua slot-fillers. If objects altogether go, whatever remains can be called ‘structure’ only if we take ‘structure’ to be a term of art. Well, Ontic Structuralists are happy to ‘mimic’ talk of non-structure, or objects in particular, but they hasten to add that this mimicking does not imply any serious metaphysical commitment to them. Here are a couple of characteristic passages. (shrink)

Human emotional expressions can communicate the emotional state of the expresser, but they can also communicate appeals to perceivers. For example, sadness expressions such as crying request perceivers to aid and support, and anger expressions such as shouting urge perceivers to back off. Some contemporary artificial intelligence (AI) systems can mimic human emotional expressions in a (more or less) realistic way, and they are progressively being integrated into our daily lives. How should we respond to them? Do we have (...) reasons to reply to the appeals made by AI emotional expressions? In this paper, we examine the conditions under which AI emotional expressions could give us prudential or even moral reasons to change our behavior. We argue that these conditions do not depend on whether the emotional expression is genuine or not, but rather on the presence of features some of which can be implemented in emotive AI given our current level of technological development. We extract recommendations and warnings for the development of emotive AI. (shrink)

In Philosophical Fragments the pseudonymous author Johannes Climacus explored the question: What is required in order to go beyond Socratic recollection of eternal ideas already possessed by the learner? Written as an afterword to this work, Concluding Unscientific Postscript is on one level a philosophical jest, yet on another it is Climacus's characterization of the subjective thinker's relation to the truth of Christianity. At once ironic, humorous, and polemical, this work takes on the "unscientific" form of a mimical-pathetical-dialectical compilation of (...) ideas. Whereas the movement in the earlier pseudonymous writings is away from the aesthetic, the movement in Postscript is away from speculative thought. Kierkegaard intended Postscript to be his concluding work as an author. The subsequent "second authorship" after The Corsair Affair made Postscript the turning point in the entire authorship. Part One of the text volume examines the truth of Christianity as an objective issue, Part Two the subjective issue of what is involved for the individual in becoming a Christian, and the volume ends with an addendum in which Kierkegaard acknowledges and explains his relation to the pseudonymous authors and their writings. The second volume contains the scholarly apparatus, including a key to references and selected entries from Kierkegaard's journals and papers. (shrink)

My dissertation focuses on the moral philosophy of Descartes, Pascal, and Spinoza in the context of the revival of Stoicism within the seventeenth century. There are many misinterpretations about early modern ethical theories due to a lack of proper awareness of Stoicism in the early modern period. My project rectifies this by highlighting understated Stoic themes in these early modern texts that offer new clarity to their morality. Although these three philosophers hold very different metaphysical commitments, each embraces a different (...) aspect of Stoicism, letting it influence but not define his work. By addressing the Stoic themes on the morality of these three authors, I also hope to help better capture the intellectual climate of the time by bringing Stoic themes into the foreground. Stoicism is a Hellenistic philosophy that considered the passions a sickness of the intellect and the source of all human suffering; they believed the cure was virtue, which was obtained through replacing irrational passions with rational beliefs. Stoicism had a revival in the Renaissance ushering in a wave of Neostoic authors who play an important role in shaping the intellectual landscape of the following centuries. My first two chapters discuss Descartes, who wrote a “provisional morality” early in his public life, only (as I show) to ignore the subject of ethics until near his death. In my first chapter I argue that, though many present-day scholars misread Descartes’ first ethics as part of his final ethics, this earliest “provisional morality” mimics Neostoic Skeptics such as Montaigne and is provisional because his method of doubt is also provisional. In my second chapter I show that Descartes’ late, and more developed, moral theory attempts to synthesize a variety of ancient, and seemingly contradictory, ethical traditions: Stoicism, Epicureanism, and Aristotelianism. In many ways Descartes embraces Stoic morality, but as a mechanist he does not view passions as an intellectual sickness; rather they are a physiological event, an amoral instrument that can be used to help control one’s irrational desires. I further defend my thesis externally by showing that this is the reading supported by Descartes’ contemporaries including critics such as Leibniz and early Cartesians such as Antoine Le Grand and Pierre-Sylvain Régis My third chapter discusses Pascal, who embraces Stoicism differently. Pascal offers Stoicism as the first tier of a binary ethics: modeled after Augustine’s city of God and city of man, it is an alternative moral code for those who are ignorant of the good and true happiness. Finally, in my fourth chapter, I discuss two common misinterpretations of Spinoza’s ethics: one of them neglects the Stoic influence on his thought while the other embraces it too strongly, portraying him as an unadulterated Stoic. Although there are ways that he is more Stoic than Descartes and Pascal, such as in his panpsychism and monism, this does not extend to his morality. Rather than accepting either of the two readings, I highlight anti- Stoic themes that are also present. I conclude that if the discussion is contained to his morality, Spinoza is no more Stoic than the other Neostoics I discuss in previous chapters. (shrink)

Light can kill the photoreceptors of the eye, not only very bright direct sunlight, but more moderate illumination if the light is present continuously. Recent experiments show that rod apoptosis can be triggered by strong and constant activation of transduction, and that death can be prevented if transduction is inhibited even though the eye is illuminated. Vitamin A deficiency and genetically inherited diseases, such as some forms of retinitis pigmentosa and Leber congenital amaurosis, appear to kill like this: transduction is (...) activated at a high rate and continuously, and this causes the rods to die. Why does transduction kill? Our best guess is that continuous activation produces a prolonged lowering of the Ca2+ concentration, which is also thought to kill neurons in tissue culture and during the development of the nervous system. To prevent death in constant light, rods have evolved protective mechanisms including modulation of channels and ion transport to keep the Ca2+ from going too low. Prolonged light exposure also causes migration of transduction proteins from one part of the cell to another and a reversible shortening of the rod outer segments, the part of the cell that contains the pigment rhodopsin. All of these mechanisms are at work in the normal eye to reduce transduction and prevent the Ca2+ concentration from dropping too low for too long a time. That most of us retain our vision our entire lives is a testament to their effectiveness. BioEssays 28: 344–354, 2006. © 2006 Wiley Periodicals, Inc. (shrink)