Philosophy of perception: Encyclopedia II - Philosophy of perception - Philosophical ideas about perception

Philosophy of perception - Philosophical ideas about perception

The most common theory of perception is naïve realism in which people believe that what they perceive is things in themselves. Children develop this theory as a working hypothesis of how to deal with the world. Many people who have not studied biology carry this theory into adult life and regard their perception to be the world itself rather than a pattern that overlays the form of the world. Thomas Reid took this theory a step further, he realised that sensation was composed of a set of data transfers but declared that these were in some way transparent so that there is a direct connection between perception and the world. This idea is called Direct Realism. Direct Realism has become popular in recent years with the rise of postmodernism and Behaviourism. Direct Realism does not clearly specify the nature of the bit of the world that is an object in perception, especially in cases where the object is something like a silhouette.

The succession of data transfers that are involved in perception suggests that somewhere in the brain there is a final set of activity, called sense data, that is the substrate of the percept. Perception would then be some form of brain activity and somehow the brain would be able to perceive itself. This concept is known as indirect realism. In Indirect Realism it is held that we can only be aware of external objects by being aware of representations of objects. This idea was held by John Locke and Immanuel Kant. The common argument against indirect realism, used by Gilbert Ryle amongst others, is that it implies a homunculus or Ryle's regress where it appears as if the mind is seeing the mind in an endless loop. This argument assumes that perception is entirely due to data transfer and classical information processing. This assumption is highly contentious (see strong AI) and the argument can be avoided by proposing that the percept is a phenomenon that does not depend wholly upon the transfer and rearrangement of data.

Direct realism and indirect realism are known as 'realist' theories of perception because they hold that there is a world external to the mind. Direct realism holds that the representation of an object is located next to, or is even part of, the actual physical object whereas indirect realism holds that the representation of an object is brain activity. Direct realism proposes some as yet unknown direct connection between external representations and the mind whilst indirect realism requires some feature of modern physics to create a phenomenon that avoids infinite regress. Indirect realism is consistent with experiences such as:

binding, dreams, imaginings, hallucinations, illusions, the resolution of binocular rivalry, the resolution of multistable perception, the modelling of motion that allows us to watch TV, the sensations that result from direct brain stimulation, the update of the mental image by saccades of the eyes and the referral of events backwards in time

whereas direct realism argues either that these experiences do not occur or avoids the problem by defining perception as only those experiences that are consistent with direct realism.

Apart from the realist theories of perception there are also anti-realist theories. There are two varieties of anti-realism: Idealism and Skepticism. Idealism holds that we can only be aware of mental things whereas skepticism holds that because we never perceive external objects directly we can never know for certain whether they exist. One of the most influential proponents of idealism was George Berkeley who maintained that everything was mind or dependent upon mind. Berkeley's idealism has two main strands, phenomenalism in which physical events are viewed as a special kind of mental event and subjective idealism. David Hume is probably the most influential proponent of skepticism.

The philosophy of perception is very closely related to a branch of philosophy known as epistemology, the theory of knowledge, and many of the ideas presented above are also discussed under this heading.

The term neuro-linguistic programming, often abbreviated to NLP, was coined by Richard Bandler and John Grinder for their method of studying the structure of subjective experience.

Adapted from the Wikipedia article "Philosophical ideas about perception", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki