|Disputed term/author/ism||Author Vs Author
|Peacocke, Chr.||Tradition Vs Peacocke, Chr.||I 17/18
Translation/Perception TheoryVsPeacocke: natural reaction: the statements that seem to conflict with the adequacy thesis (AT) could be translated into statements that do not add any properties incompatible with the adequacy thesis. For example, "in order to cover the closer tree, a larger area would have to be pushed between the tree and the observer than for the more distant tree".
PeacockeVsPerception Theory/PeacockeVsAdequacy Thesis: it is not clear how this should work against the second kind of example. But does it work against the first?
What should the translation explain?
1. It could explain why we use the same spatial vocabulary for both three-dimensional objects and the visual field. That is enough for "above" or "beside".
But the adequacy theory needs more than that! It needs an explanation why something is bigger than something else in the visual field. So. 2. problem: as an access that introduces meanings, the access of the adequacy thesis seems inadequate. Example disturbances in the visual field, curved rays ... + ..
Counterfactual: Problem: whether an object is larger in a subject's field of vision is a property of its experience. In the real world counterfactual circumstances are as they wish. An approach should therefore only take into account the properties of actual perception.
Translation/Peacocke: a distinction between acceptable and unacceptable components can be made with Kripke's distinction between fixation of the speaker and the meaning of an expression: Kripke: for example: one could fix the reference of the name "Bright" by demanding that it should refer to the man who invented the wheel. ((s) Evans: Example Julius, the inventor of the zipper).
N.B.: nevertheless the sentence is true: "it is possible that Bright never invented the wheel".
Peacocke: analog: the experience of the type that the closer tree is larger in the field of vision agrees that a larger piece must be covered to make it invisible.
This condition fixes the type of experience. But it would be possible that the type of experience does not meet the condition! Just as Bright did not have to be the inventor of the wheel.
PeacockeVsPerception Theory: Translation: does not provide an approach that leaves the possibility open that the type of experience that actually satisfies the conditions of translation might fail.
|Tradition||Peacocke Vs Tradition||I 4
Perception/Peacocke: Thesis: sensation concepts (sensory perception, sensations) are indispensable for the description of any perception. VsTradition: against the view that sensations are not to be found in the main stream if the subject is to concentrate on its own perception, I 5 or when sensations occur as a byproduct of perception. Perception/Sensation/Tradition/Peacocke: historical distinction between perceptions (perceptual experience) that have a content, namely being propositionally (representational) about objects in the surroundings that appear in a certain way, and sensations: that have no such content, e.g. the sensation of smallness, which can be determined nonetheless.
Content/Peacocke: I only use it for the representational content of perceptions. Never for sensations. PeacockeVsTradition: it used to be reversed and "object" or "meaning" were used for representational content.
Extreme Theory of Perception/Peacocke: the adequacy thesis is obliged. Because if the adequacy thesis is wrong, there are intrinsic properties of visual perception that are not covered by the representational content. Representatives: Hintikka. Hintikka: the right way to speak about our spontaneous perceptions is to use the same vocabulary and the same syntax that we apply to the objects of perception. We just need to determine the information! Information/Hintikka: unlike here: no informational content, but information given by the perception system. I 11 extreme theory of perception: main motivation. If the adequacy thesis is false, then there are intrinsic properties of an experience that can never be known by the person who makes the experience! PeacockeVs: this may be strengthened by the following argument that superficially seems correct: we can tell what experiences someone makes if we know which are his desires or intentions. Or if he is so and so predisposed. Or his behavior: E.g. if he suddenly swerves, he may have perceived an obstacle. Point: this can only ever discover representational content! I.e. never the intrinsic (perhaps sensory) portion of the experience. Peacocke: there must be a gap here. Three counter-examples are to show this. (see below).
Perception/Peacocke: is always more differentiated than the perception concepts!
Qualia/Criterion/Goodman: identity conditions for qualia: >N. Goodman, The Structure of Appearance, 1951 p.290
Extreme Theory of Perception/Peacocke: claims that the intrinsic properties of a visual experience are exhausted in determining the representational content along with a further-reaching determination of the properties mentioned there.
PeacockeVsTheory of Perception: Three counter-examples: 1) E.g. road straight to the horizon with two trees. We perceive the trees as different in size, but we know (or assume) that they are the same size and at different distances from us. Both versions are equally properties of the experience itself! For this we do not need concepts like perception field (visual field), which is more or less cut out by the tree. You simply have the experience. VsAdequacy Thesis: no true-making experience can represent one tree as larger and farther away or the other as a smaller and closer. Problem of additional characterization. Form of thought: added second or third. VsTheory of Perception: the challenge for the perception theorist is that has to hold on to the adequacy thesis (all intrinsic characterization given by "appears to the subject that...") even if he has to admit these facts about the size of trees. I 13 2) Additional characterization: can vary even if the representational content remains constant: E.g. seeing with one eye closed or with both eyes open: the difference in perception is independent of the double images of binocular perception. I 14 Depth Perception/Peacocke:
a) It would be incompatible with our view to say that there is an additional way in which the depth is represented, with this additional feature being purely representational. b) The difference between monocular and binocular vision is both representational and sensory. (Peacocke pro). Vs a): here it would be unthinkable that there are cases where the alleged sensory property exists, but the representation of certain objects was not present behind others in the surroundings. pro b): according to this version that is conceivable. I 15 Peacocke: and it is also conceivable. E.g. TVSS: a system that "writes" information from a TV camera on the back of blind persons: idea of depth and spatial perception. Intrinsic!
"Depth"/Peacocke: dangerous ambiguity: it is true that whenever the additional property is present that distinguishes monocular of binocular vision, then a sense of depth is present, but depth is a sensational property! I 16 I.e. the difference between monocular and binocular vision is precisely not purely representational! (Peacocke pro: in addition to representational there must be sensory content). Depth/Perception/Concepts/O'ShaughnessyVsPeacocke: depth is never a sensational property: concepts play a causal role in the creation of depth: 1) every depth perception depends on you considering your visual sensation of depth as a contribution to the color of physical objects at any distance. 2) monocular vision: two visual fields of sensations might be indistinguishable, and yet, thanks to different concepts and different beliefs of their owners, evoke different veridical visual "depth impressions". But: binocular vision: here the three-dimensional visual field properties cannot be compared with different sensations of depth, at least not with regard to the three-dimensional distribution of the actually viewed surface. PeacockeVsO'Shaughnessy: that is indeed confirmed by the optical facts, but he only considers the beams that fall into a single eye! In fact, monocular vision is insufficient for depth perception. Binocular vision not only explains the sensation of depth, but also why this property decreases at large distances.
PeacockeVsTheory of Perception:
3) E.g. tipping aspect, wire cube, first seen with one eye, and then without any modification of the cube with reversed front and rear: Wittgenstein: "I see that it has not changed"! Peacocke: another example of non-representational similarities between experiences. The problem for the extreme perception theorist is to explain how these non-representational similarities came to pass without abandoning the adequacy thesis. He could simply introduce a new classification of visual experience, I 17 that refers to something before the event of experience, for example, the fact that the surroundings have not changed. PeacockeVs: but this is based on the character of successive experiences! Then we would still have to say on which properties of these experiences this "new property (classification)" is based. This does not work with memory loss or longer time spans between experienced: because this does not require the sensation that the scene has not changed. Nor does it explain the matching non-representational experiences of two different subjects who both see the other side of the cube as the front.
Rabbit-Duck Head/Peacocke: why do I not use it as an example? Because there is nothing here that is first seen as a rabbit and then as a duck, but rather as a representation of a rabbit than as a representation of a duck, while nothing changes in the network of lines! So this example cannot explain that there may be non-representational similarities between experiences. Because someone who denies them can simply say that the component of the representational content that relates to the lines remains constant thus explaining the similarity. E.g. wire cube: here this explanation is not possible: because the network of lines looks quite different afterwards than it did before!
Translation/Theory of PerceptionVsPeacocke: natural reaction: the statements which seem to be in conflict with the adequacy thesis could be translated into statements that add no properties incompatible with the adequacy thesis. E.g. "to cover the nearer tree, a larger area would have to be put between the tree and the viewer than for the more distant tree". PeacockeVsTheory of Perception/PeacockeVsAdequacy Thesis: it is not clear how this is supposed to work against the second type of example. But is it effective against the first one? What should the translation explain? 1) It could explain why we use the same spatial vocabulary for both three-dimensional objects and for the field of vision. That is also sufficient for "above" or "next to". But the adequacy thesis needs more than that! It needs an explanation for why something is bigger than something else in the field of vision. Therefore:
2) Problem: as approach which introduces meanings the approach of the adequacy thesis seems inadequate. E.g. disturbances in the visual field, curved beams ...+... counterfactual: problem: whether an object is bigger in the visual field of a subject is a property of its experience that in the real world counterfactual circumstances are what they want to be. One approach should therefore only take into account the properties of actual perception. I 19 Translation/Peacocke: a distinction between acceptable and unacceptable components can be made with Kripke's distinction between fixation of the reference and the meaning of an expression: Kripke: E.g. we could fix the reference of the name "Bright" by the fact that demanding that he should refer to the man who invented the wheel. ((s) Evans: E.g. Julius, the inventor of the zipper). Point: yet the statement is true: "it is possible that Bright never invented the wheel". Peacocke: analog: the experience of the type that the nearer tree in the field of vision is bigger is consistent with the fact that a larger area has to be covered to make it invisible. This condition fixes the type of experience. But it would be possible that the experience type does not satisfy the condition! Just like Bright would not have needed to be the inventor of the wheel. PeacockeVsTheory of Perception: Translation: provides no access that leaves open the possibility that the experience type that actually meets the conditions of the translation, might as well fail.
Sensational Content/PeacockeVsTheory of Perception: these points refer to the first counter-example against the adequacy thesis, but they also apply to the second one: for that purpose, we introduce the asterisked predicate behind*: it refers in terms of physical conditions that normally produce this sensational quality binocular seeing of objects at different depths. ad 3): non-representational similarity of experiences should consist in sameness or equality of sensational properties. Reversible Figures: in all standard cases, successive experiences have the same asterisked sensational properties: namely, those that can be expressed by the presented interposed coverage area. E.g. suppose someone wakes up in unfamiliar surroundings: initially he has a minimal representational content: he perceives all objects as surfaces with different angles. I 23 Suddenly everything shifts into place and he has a rich representational content. But in the scene nothing has changed in the sense in which something changed in the wire cube.
Chr. R. Peacocke
Sense and Content Oxford 1983
"Truth Definitions and Actual Languges"
Truth and Meaning, G. Evans/J. McDowell Oxford 1976