Visual Experience: Cognitive Penetrability and Indeterminacy

This paper discusses a counterexample to the thesis that visual experience is cognitively impenetrable. My central claim is that sometimes visual experience is influenced by the perceiver’s beliefs, rendering her experience’s representational content indeterminate. After discussing other examples of cognitive penetrability, I focus on a certain kind of visual experience— that is, an experience that occurs under radically nonstandard conditions—and show that it may have indeterminate content, particularly with respect to low-level properties such as colors and shapes. I then explain how this indeterminacy depends on the perceiver’s beliefs or thoughts. Finally, I attempt to generalize the case and show how other sorts of visual experiences can also be penetrated by beliefs and, hence, be indeterminate.     

Trust and Contextualism

The objective of this paper is to apply the general idea of contextualism, as a theory of knowledge attribution, to the very specific case of testimony and trust characterized as being the procedure of the attribution of knowledge (and sincerity) to the informant. In the first part, I argue in favor of evidentialism, a viewpoint that takes epistemically responsible trust as a matter of evidence. In the second part, I consider the question of how strong an evidential basis has to be for epistemically responsible trust. I have briefly registered two main tendencies in contemporary debates regarding trust and testimony: (i) the non-unitary character of our trust; (ii) and the requirement for a refinement of evidential standards. In short, I argue in favor of the stance that any ‘undiscriminatory generalization’ (both Redian or anti-reductivist and Humean or reductivist) concerning epistemically responsible trust is a kind of inappropriate theoretical idealization, and that a certain theoretical reconciliation has to be offered. Finally, in the third part, I propose trust-contextualism as the viewpoint that optimally harmonizes both our intuitive and theoretical requirements about epistemically responsible trust.

A Defense of McDowell’s Response to the Sceptic

Crispin Wright argues that John McDowell’s use of disjunctivism to respond to the sceptic misses the point of the sceptic’s argument, for disjunctivism is a thesis about the differing metaphysical natures of veridical and nonveridical experiences, whereas the sceptic’s point is that our beliefs are unjustified because veridical and nonveridical experiences can be phenomenally indistinguishable. In this paper, I argue that McDowell is responsive to the sceptic’s focus on phenomenology, for the point of McDowell’s response is that it is the phenomenal character of experience that makes the belief in disjunctivism rational, and thereby also makes rational the anti-sceptical belief that, other things being equal, the world is the way it appears.     

Moore-paradoxical Assertion,Fully Conscious Belief and the Transparency of Belief

I offer a novel account of the absurdity of Moore-paradoxical assertion in terms of an interlocutor’s fully conscious beliefs. This account starts with an original argument for the principle that fully conscious belief collects over conjunction. The argument is premised on the synchronic unity of consciousness and the transparency of belief.     

The parity of Farey denominators and the Farey index

A function E(b,s) is defined on the set implicitly, by a functional equation. Various conjectures arise from tables and some of these are proved. This function is then related to a partial sum of Farey indices weighted according to the parity of the Farey denominators. An explicit formula for E(b,s) is given, together with sharp bounds, and these show that the weighted partial sums of Farey indices are much smaller than expected. The explicit formula was determined from numerical trials: the question arises whether a constructive derivation from the functional equation should be possible in these and similar circumstances.     

系统讲授数学内容,激发大学生创新思维

针对大众化教育背景下的地方院校学生,以某个知识点为核心系统讲授数学内容,这是激发学生创新思维的重要途径。教学时以书本知识为载体,从显性知识、隐性内容及认知方式三个方面进行系统的讲授,旨在达到促进学生掌握数学工具和增进理性思维的同时,还能实现以创新教学激发创新思维的目的。     

Perception and Virtue Reliabilism

In some recent work, Ernest Sosa rejects the “perceptual model” of rational intuition, according to which intuitive beliefs (e.g., that 2 + 2 = 4 2 + 2 = 4 ) are justified by standing in the appropriate relation to a nondoxastic intellectual experience (a seeming-true, or the like), in much the way that perceptual beliefs are often held to be justified by an appropriate relation to nondoxastic sense experiential states. By extending some of Sosa’s arguments and adding a few of my own, I argue that Sosa is right to reject the perceptual model of intuition, and that we should reject the “perceptual model” of perception as well. Rational intuition and perception should both receive a virtue theoretic (e.g., reliabilist) account, rather than an evidentialist one. To this end, I explicitly argue against the Grounds Principle, which holds that all justified beliefs must be based on some adequate reason, or ground.     

Ownership, Authorship and External Justification

Some of the most well-known arguments against epistemic externalism come in the form of thought experiments involving subjects who acquire beliefs through anomolous means such as clairvoyance. These thought experiments purport to provide counterexamples to the reliabilist conception of justification: their subjects are intuitively epistemically unjustified, yet meet reliabilist externalist criteria for justification. In this article, I address a recent defence of externalism due to Daniel Breyer, who argues that externalists need not consider such subjects justified, since they fail to own those beliefs in a way required for epistemic evaluability. I argue that the concept of belief ownership Breyer adopts leaves his account open to related counterexamples, and suggest a modification, drawing on analogies between these cases and cases of delusions, such as thought insertion. I will argue that a concept of authorship developed in the literature on delusions better grounds the sense of attribution required for epistemic evaluability.     

Varieties of Pragmatic Encroachment

According to a recent view, known as the 'pragmatic encroachment' thesis, an agent’s non-truth-related factors are relevant to the epistemic status of her beliefs. In particular, in addition to truth-related factors, practical factors are said to be relevant to the question whether or not true belief amounts to knowledge. Despite the intuitive appeal of the thesis, however, it is puzzling how practical factors can impact the truth-related factors that ground the epistemic status of one's beliefs. In this paper, I will distinguish between a strong and a weak sense of the way in which practical factors are said to be thus relevant. Their differences are explicated in terms of the nature and the extent to which practical factors are said to impact the epistemic status of one's beliefs. I begin by considering a strong version of the thesis that suggests principles according to which the practical rationality of one's actions is a necessary condition on knowledge and justification. Having noted an inadequacy in the formulation of such principles, the arguments in their support are subsequently stated and criticized. Finally, I identify two modest versions of the thesis of pragmatic encroachment and argue that they, too, fail to explain how practical factors can bear on the epistemic status of one's beliefs.     

基于因子分析的元认知外语教学策略研究

从心理学、第二语言习得理论出发,研究了场独立与场依存认知风格的外语学习者特点,应用因子分析数学模型,进行了培养元认知策略意识及发展双重认知风格等教学策略的教学实验,仿真实验表明了该方法的实用性和有效性.     

Consciousness as a state of matter

We examine the hypothesis that consciousness can be understood as a state of matter, “perceptronium”, with distinctive information processing abilities. We explore four basic principles that may distinguish conscious matter from other physical systems such as solids, liquids and gases: the information, integration, independence and dynamics principles. If such principles can identify conscious entities, then they can help solve the quantum factorization problem: why do conscious observers like us perceive the particular Hilbert space factorization corresponding to classical space (rather than Fourier space, say), and more generally, why do we perceive the world around us as a dynamic hierarchy of objects that are strongly integrated and relatively independent? Tensor factorization of matrices is found to play a central role, and our technical results include a theorem about Hamiltonian separability (defined using Hilbert–Schmidt superoperators) being maximized in the energy eigenbasis. Our approach generalizes Giulio Tononi’s integrated information framework for neural-network-based consciousness to arbitrary quantum systems, and we find interesting links to error-correcting codes, condensed matter criticality, and the Quantum Darwinism program, as well as an interesting connection between the emergence of consciousness and the emergence of time.     

On Knowing How I Feel About That—A Process-Reliabilist Approach

Human subjects seem to have a type of introspective access to their mental states that allows them to immediately judge the types and intensities of their occurrent emotions, as well as what those emotions are about or “directed at”. Such judgments manifest what I call “emotion-direction beliefs”, which, if reliably produced, may constitute emotion-direction knowledge. Many psychologists have argued that the “directed emotions” such beliefs represent have a componential structure, one that includes feelings of emotional responses and related but independent representations of what those feelings are about. I argue that such componentiality may help to explain how emotion-direction knowledge is achievable. I begin by developing a hybrid view of introspection that combines David Chalmers’ phenomenal realism with Alvin Goldman’s “partial redeployment” account of meta-belief content. I then provide a process-reliabilist account of introspectively gained emotion-direction knowledge that outlines the minimum conditions of reliably forming emotion-direction beliefs, and specifies several ways in which the warrant of such beliefs could be defeated by relevant counterfactual alternatives. The overall account suggests how distinct introspective processes might be epistemically synergistic.     

Value differences using second-order distributions

Most decision models for handling vague and imprecise information are unnecessarily restrictive since they do not admit for discrimination between different beliefs in different values. This is true for classical utility theory as well as for the various interval methods that have prevailed. To allow for more refined estimates, we suggest a framework designed for evaluating decision situations considering beliefs in sets of epistemically possible utility and probability functions, as well as relations between them. The various beliefs are expressed using different kinds of belief distributions. We show that the use of such distributions allows for representation principles not requiring too hard data aggregation, but still admitting efficient evaluation of decision situations.     

Large-scale linear programming: Geometry,working bases and factorizations

This paper is concerned with linear programming problems in which many of the constraints are handled implicitly by requiring that the vector of decision variables lie in a polyhedronX. It is shown that the simplex method can be implemented using a working basis whose size is the number of explicit constraints as long as the local structure ofX around the current point is known. Various ways of describing this local structure lead to known implementations whenX is defined by generalized or variable upper bounds or flow conservation constraints. In the general case a decomposition principle can be used to generate this local structure. We also show how to update factorizations of the working basis.     

Revising beliefs on the basis of evidence

Approaches to belief revision most commonly deal with categorical information: an agent has a set of beliefs and the goal is to consistently incorporate a new item of information given by a formula. However, most information about the real world is not categorical. In revision, one may circumvent this fact by assuming that, in some fashion or other, an agent has elected to accept a formula ?, and the task of revision is to consistently incorporate ? into its belief corpus. Nonetheless, it is worth asking whether probabilistic information and noncategorical beliefs may be reconciled with, or even inform, approaches to revision. In this paper, one such account is presented. An agent receives uncertain information as input, and its probabilities on (a finite set of) possible worlds are updated via Bayesian conditioning. A set of formulas among the noncategorical beliefs is identified as the agent’s categorical belief set. The effect of this updating on the belief set is examined with respect to its appropriateness as a revision operator. We show that few of the classical AGM belief revision postulates are satisfied by this approach. Most significantly, though not surprisingly, the success postulate is not guaranteed to hold. However it does hold after a sufficient number of iterations. As well, it proves to be the case that in revising by a formula consistent with the agent’s beliefs, revision does not correspond to expansion. Postulates for iterated revision also examined, and it proves to be the case that most such postulates also do not hold. On the other hand, limiting cases of the presented approach correspond to specific approaches to revision that have appeared in the literature.     

Reliabilism and Brains in Vats

According to epistemic internalism, the only facts that determine the justificational status of a belief are facts about the subject’s own mental states, like beliefs and experiences. Externalists instead hold that certain external facts, such as facts about the world or the reliability of a belief-producing mechanism, affect a belief’s justificational status. Some internalists argue that considerations about evil demon victims and brains in vats provide excellent reason to reject externalism: because these subjects are placed in epistemically unfavorable settings, externalism seems unable to account for the strong intuition that these subjects’ beliefs are nonetheless justified. I think these considerations do not at all help the internalist cause. I argue that by appealing to the anti-individualistic nature of perception, it can be shown that skeptical scenarios provide no reason to prefer internalism to externalism.     

Content essentialism

The paper offers some preliminary and rather unsystematic reflections about the question: Do Beliefs Have Their Contents Essentially? The question looks like it ought to be important, yet it is rarely discussed. Maybe that’s because content essentialism, i.e., the view that beliefs do have their contents essentially, is simply too obviously and trivially true to deserve much discussion. I sketch a common-sense argument that might be taken to show that content essentialism is indeed utterly obvious and/or trivial. Somewhat against this, I then point out that a “sexy” conclusion that is sometimes drawn from Putnam-Burge-style externalist arguments, namely that our mental states are not in our heads, presupposes content essentialism — which suggests that the view is not entirely trivial. Moreover, it seems intuitively that physicalists should reject the view: If beliefs are physical states, how could they have their propositional contents essentially? I distinguish three readings of the title question. Content essentialism does seem fairly obvious on the first two, but not so on the third. I argue that the common-sense argument mentioned earlier presupposes one of the first two readings but fails to apply to the third, on which ‘belief’ refers to belief-state tokens. That’s because ordinary belief individuation is silent about belief-state tokens. Token physicalists, I suggest, should indeed reject content essentialism about belief-state tokens. What about token dualists? One might think they ought to embrace content essentialism about belief-state tokens. I end with puzzling why this should be so.     

A systematization of the saddle point method. Application to the Airy and Hankel functions

The standard saddle point method of asymptotic expansions of integrals requires to show the existence of the steepest descent paths of the phase function and the computation of the coefficients of the expansion from a function implicitly defined by solving an inversion problem. This means that the method is not systematic because the steepest descent paths depend on the phase function on hand and there is not a general and explicit formula for the coefficients of the expansion (like in Watson's Lemma for example). We propose a more systematic variant of the method in which the computation of the steepest descent paths is trivial and almost universal: it only depends on the location and the order of the saddle points of the phase function. Moreover, this variant of the method generates an asymptotic expansion given in terms of a generalized (and universal) asymptotic sequence that avoids the computation of the standard coefficients, giving an explicit and systematic formula for the expansion that may be easily implemented on a symbolic manipulation program. As an illustrative example, the well-known asymptotic expansion of the Airy function is rederived almost trivially using this method. New asymptotic expansions of the Hankel function Hn(z) for large n and z are given as non-trivial examples.     

Generalized explicit inversive generators of small p-weight degree

Using rational functions to generate pseudorandom number sequences is a popular research topic. In this paper, we study bounds on additive character sums of a new explicit generator based on rational functions with small p-weight degree. This extends the class of functions where a nontrivial character sum bound is known.     

Estimation,model discrimination,and experimental design for implicitly given nonlinear models of enzyme catalyzed chemical reactions

Many nonlinear models as e.g. models of chemical reactions are described by systems of differential equations which have no explicit solution. In such cases the statistical analysis is much more complicated than for nonlinear models with explicitly given response functions. Numerical approaches need to be applied in place of explicit solutions. This paper describes how the analysis can be done when the response function is only implicitly given by differential equations. It is shown how the unknown parameters can be estimated and how these estimations can be applied for model discrimination and for deriving optimal designs for future research. The methods are demonstrated with a chemical reaction catalyzed by the enzyme Benzaldehyde lyase.