Online research in philosophy

What is the difference between perception and mere sensation? Take a typical perceptual experience, such as an experience of seeing a fish or a table, and a merely sensory experience, such as the experience of.

It is sometimes said that in depression, everything looks grey. If this is true, then mood can influence the character of perceptual experience: depending only on whether a viewer is depressed or not, how a scene looks to that viewer can differ even if all other conditions stay the same. This would be an example of cognitive penetrability of visual experience by other mental states. Here the influential cognitive state is a mood. Other putative examples of cognitive penetrability involve beliefs: (...) to the reader of Russian, the sheet of Cyrillic script looks different than it looked to her before she could read it. When you know that bananas are yellow, this knowledge affects what color you see bananas to be (an achromatic banana will [2] appear yellowish). To the vain performer, the faces in the audience range in their expression from neutral to pleased, but remarkably no one ever looks disapproving. To the underconfident performer, the faces in the audience range in their expression from neutral to displeased, but remarkably no one ever looks approving. And in cases of suggestibility, the mere salience of a hypothesis seems to have an effect on how a given stimulus is experienced. Potential cognitive penetrators thus include moods, beliefs, hypotheses, knowledge, desires, and traits. In some cases, cognitively penetration can be epistemically beneficial. If an x ray looks different to a radiologist from the way it looks to someone lacking radiological expertise, then the radiologist gets more information about the world from her experience (such as whether there’s a tumor) than the non expert does from looking at the same x ray. If Iris Murdoch and John McDowell are right that having the right sort of character lets you see more moral facts than someone lacking that character sees when faced with the same situation, then there too your perceptual experience becomes epistemically better thanks to its being penetrated by your [3] character. In other cases, however, cognitive penetration seems to make experience epistemically worse.. (shrink)

If you want to know whether there is any mustard in the refrigerator, it is a good idea to open the door and look. If you see the mustard, you can end up knowing its whereabouts: it’s in the fridge. If instead of looking for the mustard, you pictured the fridge interior in a daydream, and then relied on your daydream to confirm whether the fridge contained mustard or not, you wouldn’t end up knowing anything about the mustard or the (...) fridge. At best you would end up with a true belief. As the mustard example illustrates, it is part of common practice to regard perception as a special kind of input to belief that allows us to compare hypotheses with the world, so that we may assess whether those hypotheses are true. Even philosophers who were cautious about assigning perception more than a causal role in relation to knowledge regard perception as involving a special sort of input, different in kind from belief and judgment. For instance, Locke distinguished ideas of sensation from ideas of reflection, and Hume distinguished impressions from ideas. Both in common practice and in philosophy, perception is regarded as a distinctive kind of mental state that serves as an input to belief, and is distinct from it. It is one thing to regard perceptual states as distinct from belief, but another to say what is distinctive about them. What distinguishes perceptual states from beliefs, daydreams, and all other kinds of mental states? In this paper I address this question for a specific class of perceptual states: conscious visual experiences, where these are the kind of experience one typically has in seeing one’s environment, or are [1] introspectively indistinguishable from them. Conscious visual experiences thus include visual hallucinations that are introspectively indistinguishable from veridical perceptions. I argue that visual perceptual experiences share an important feature with beliefs: they have contents, in a sense to be explained. Given this similarity between visual experiences and beliefs, their distinctness from belief must be found either in a further structure from which their contents have been derived, from a special mode of entertaining contents (distinct from the mode found in belief). My discussion will focus on interpreting, developing and defending the following thesis: The Content View: All visual perceptual experiences have contents. The kind of content at issue meets two constraints: contents are true or false, and contents of experience are conveyed to the subject by her experience.. (shrink)

How is causation represented in the mind? We often believe that one event has caused another. But can we visually experience two things as causally related? If so, then experiences represent causation. A different question in the vicinity is whether we can ever see that something is causing (or has just caused) something else to happen. In the relevant sense of ‘seeing’ here, seeing is factive – you can see that p only if p. By contrast, experiential representation of properties (...) or relations is not factive, so you can represent that p even if p is not true. (shrink)

Early formulations of disjunctivism about perception refused to give any positive account of the nature of hallucination, beyond the uncontroversial fact that they can in some sense seem to the same to the subject as veridical perceptions. Recently, some disjunctivists have attempt to account for hallucination in purely epistemic terms, by developing detailed account of what it is for a hallucinaton to be indiscriminable from a veridical perception. In this paper I argue that the prospects for purely epistemic treatments of (...) hallucinations are dim, and that this undermines the case for disjunctivism. (shrink)

In this paper I discuss several proposals for how to find out which contents visual experiences have, and I defend the method I.

The expressions this cat and that glove with a hole in it are complex demonstratives. In this paper, we defend a thesis about complex demonstratives. The thesis we defend concerns the role of the nominal (e.g., cat and glove with a hole) in a central class of uses. In the utterances at issue, we argue, the nominal F in that F plays a policing role: no proposition is semantically expressed by the utterance, if the object appropriated by the speaker’s use (...) of that F fails to be F. We'll call this nominal policing. (shrink)

Perception provides a form of contact with the world and the other people in it. For example, we can learn that Franco is sitting in his chair by seeing Franco; we can learn that his hair is gray by seeing the colour of his hair. Such perception enables us to understand primitive forms of language, such as demonstrative expressions.

In discussions of perception and its provision of knowledge, it is common to distinguish what one comes to believe on the basis of perception from the distinctively perceptual basis of one's belief. The distinction can be drawn in terms of propositional contents: there are the contents that a perceiver would normally come to believe on the basis of her perception, on the one hand; and there are the contents properly attributed to perception itself, on the other. Consider the content.

What is the difference between perception and mere sensation? Take a typical perceptual experience, such as an experience of seeing a fish or a table, and a merely sensory experience, such as the experience of ‘seeing stars’ or of enjoying a red phosphene (a phosphene is a kind of afterimage). One difference between these experiences is that in the first case, there is an external object that one sees. But this difference is not the only difference. On the face of (...) it, typical perceptual experiences and mere sensations also differ in their phenomenal character. How can this difference be understood? (shrink)

Siegel defends "Limited Intentionism", a theory of what secures the semantic reference of uses of bare demonstratives ("this", "that" and their plurals). According to Limited Intentionism, demonstrative reference is fixed by perceptually anchored intentions on the part of the speaker.

First, what it is for a sentient being to sense is for it to employ two distinct capacities: one for representing places-at-times; the other for representing "features" (60, cf. 70). Exercised together, the result is akin to feature-placing, which brings us to the second thesis: what sensory systems represent is that features are instantiated at place-times. Accordingly, sensory systems do not, for instance, attribute properties to objects, such as trees, tables, bodies, or persons (163).