Theory of Perception - Essay Example

Theory of Perception As per the theory of perception, the awareness of some entity or object to be present is determined by the visualsense. If there is an apple kept on a floor, it may be viewed as red bulging object but it cannot be said firmly that it is a real apple or a bulge of wax. The consciousness confirms that an object with certain dimensions is present at the moment. The consciousness of the object being present is termed as datum.(5) The sense data are posited to describe the way things are viewed. It is found that things appear in a certain manner to somebody when a sense-datum is presented with specific properties. Sense data are essential for analyzing properties of things, which appear to us. But sense- datum theorist believe that even if we are able to see certain things in certain way, it may not necessarily reveal the reality. In another way the process of seeing includes the activity of eyes and the influence of light and surroundings.(5) Objections to Sense-Data: 1. Ontological: Visual sense may conflict with the actual physical presence of an object. The visual existence may contradict the metaphysical truths. 2. Epistemological: The posited sense-data may lead to the perception which obscures the gaining of appropriate knowledge of physical world. 3. Phenomenological: The posited sense-data does not involve other features of the physical object which are beyond the scope of visual capability. The non physical characteristics of the objects are unexplored. 4. Sense-Data & Ontological Objections: i. Physicalism: All the existing entities shall be identical with physical entities or all the physical entities shall exist as per the posited sense-data. If the sense-data contradict the physicalism it fails to gain knowledge. ii. Sense-data are perturbing and take us away from the knowledge of the existence of entities.(5) Austin's theory refuses the validity of mutually exclusive concepts of sense- data and material objects. Some entities will not fall in either or of these suits. As Austin quotes it - "One of the most important things to grasp is that these two terms, 'sense-data' and 'material things', live by taking in each other's washing - what is spurious is not one term of the pair but the antithesis itself."(2) When one concentrates on material objects, it should be treated as no sense-data; whereas when we attend the sense-data it should be treated as non-material objects. There are several examples to justify Austin's theory. One can see many things like shadows, rainbows, mirror-images, Aurora Borealis; one can perceive the scents, listen to the rustling of leaves. All these things cannot lie in the category of material entities. Such things can be termed only as the sense-data and non material objects. (1) Bertrand Russell explains the sense-data and material object concepts by considering the example of a table. A table is an oblong object with color as per the reflected light from it and viewed from particular location. No two observers can sense the same color of the table. Different parts of the table will give different reflection of colors. The surface of the table may appear smooth to the naked eye but gives a rough appearance through a microscope. Shape, Color, smoothness are the sense-data. If a real table physically exists can be called as the material object or the matter.(2) Thus the objects of our senses doesn't exist independently. Ayer proposed to find the reasons for perception and perceptual knowledge that may arise out of the first principles even though there may be different reasons. Ayer was not interested to emphasize about the mind dependence or mind independence of any entity.(1) Austin pointed out that two different objects of awareness should not be indistinguishable. He emphasized the conception of sense-data as mind dependent. If there are sense-data as the object of awareness in case of hallucination, there can be inner object of awareness for the non illusionary cases also. (1) Russell put forward the term sense-data with respect to the appearance and truth. Sense-data are the specific things perceived during the process of sensation. When one enters into a cafeteria, he senses the smell, heat of radiator, which are the sense-data. Sense-data are the mental images that we perceive from an object in the physical world. The mental images can be of different types like: visual, sense of smell, sense of tangibility, taste and auditory. (6) Different sense-data can be perceived from same object. Though sense data are directly concerned with the physical object they represent, there is no clarity about the exact relationship between them. Though different viewers perceive different sense-data from a same material object- 'table', principally all agree that they are viewing the same table. Russell therefore believes that the sense-data perceived from the physical object are interlinked in a meaningful way. Russell conceptualizes the knowledge acquired in a process as the 'Perceptual knowledge'. He also believes that we are having a store of knowledge of certain kind, termed as "a priori knowledge" (6) Russell differentiates human knowledge as knowledge by acquaintance and knowledge by description. A table or chair object can be realized from the sense-data: Shape, color, smoothness, coolness, hardness. But to acknowledge the particular object as a table or chair it needs additional knowledge than the sense-data. Such kind of knowledge is a derivative of facts and inferences, Russell terms such knowledge as "knowledge by description". In a similar fashion, just like perceptual and a priori knowledge, knowledge by acquaintance and knowledge by description work together to create the entire human knowledge.(6) Russell believed that all knowledge is built on knowledge by acquaintance, or through things we know through direct, personal experience. Russell agrees the very basic Cartesian point of view, which means he accepts that the proper foundation for philosophical inquiry is individual consciousness and perspective. Summary: Austin accepts the sense-data and material object theory as a means of awareness. He argues that we cannot perceive the material objects directly but receive it as the sense- data. He strongly refuses the mutually exclusiveness between the sense-data and the object. He also emphasizes the inner awareness of mind which otherwise may be true in case of non hallucination perceptions. Russell points out that the objects of awareness don't have independent existence. He further says that the objects of awareness along with a priori knowledge, knowledge by acquaintance and knowledge by description are essential to predict the existence of an entity. It is quite obvious that positing sense data is essential for the awareness of the object. As justified by Austin and Russell, the sense-data and material object are non mutually exclusive things. In other words sense-data necessarily represents an awareness of the object. The main problem with the theory of perception is that the sense-data exist only for a mind. One's sense-data, exist only for him and others sense-data is separate as per the individuals case. It can be said that sense-data depend for their existence or for their qualities upon one's awareness of them. It also makes it difficult to understand the awareness of non- physical sense-data. References: 1. Austin : Sense & Sensibilia Revisited 2. http://www.homepages.ucl.ac.uk/uctymfm/Lecture%20Notes/Berkeley%20Perception%20Lectures/Philosophy%20136%20handout%2014.pdf 3. (http://philosophy.hku.hk/think/phil/russell/1.php 4. http://pdf.sparknotes.com/philosophy/russell.pdf 5. Philosophy of Perception, Handout, 18 October 2005 6. http://pdf.sparknotes.com/philosophy/russell.pdf Read More