indirect realism

• A realist believes that physical objects exist mind independent
• sense data


  the world as it appears in your mind
• indirect realism claims that the immediate objects of perception are mind-dependent objects that are caused by and represent mind-independent objects
• secondary qualities exist only when percieved
• secondary qualities are "nothing but powers" of primary qualities
• for an indirect realist perception is rooted in reality
• Indirect realism claims that we perceive physical objects mind-independently but we do so through independent sense data that are caused by and represent physical objects.
• Sense data is perceived immediately and physical objects are perceived indirectly, mediated by our peceptions
• reality is never seen but a version of it is(sense data)
• we are immediately aware of sense data
• sense data is how things appear to be
• an object exists independently, but my perception is dependent as I perceive sense data
• all we percieve is sense data produced by the object
• sense data is not a copy of the physical object but representative of that
• sense data is caused by and represents the veridical world
• sense data is the world inside your mind
• the world outside your mind causes sense data
• there is a distinction between primary and secondary qualitie
• Strengths of indirect realism

  explains perceptual variation effectively

  best hypothesis(involuntary nature of experiences and the coherence of senses)
• sense data is caused by and represens vridical perception
• How do indirect realists solve hallucinations and illusions?

  hallucinations are pure sense data - not influenced by veridical perception

  an illusion is how sense data misrepresents reality - does not resemble reality directly
• perceptual variation is as a result of different perspectives
• objects are unchangeable, outside of your mind and mind independent
• objects exist when unpercieved
• sense data is private and subjective
• some properties of objects are not in objects themselves. They are subjective and rely on a mind being present to observe them
• objects have the potential to produce subjective experiences if a perceiver appears
• Lockes argument Primary/secondary distinction


  We do not perceive objects directly. Objects cause us to have certain experiences. Therefore there is a distinction between primary, objective qualities and secondary qualities
• primary qualities are independent of any observer
• shape and weight are primary qualities
• secondary qualities are projected onto the world by percievers
• colour is a secondary quality
• primary qualities are "utterly inseparable" from the object
• primary qualities are within the ibject itself
• colour sound and taste are secondary qualities
• primary qualities are properties which are not related by definition to percievers
• Lockes grain of wheat example

  a grain of wheat divided will still retain key qualities like its solidity and figure. these qualities are primary qualities as they are "utterly inseparable" from the object
• secondary qualities are nothing in objects themselves but the powers to produce various sensations
• temperature is a secondary quality as it is subjective to our senses. For example, if the hand is dipped in hot water and then placed in lukewarm water it would feel cold relative to the hotter temperature. Similarly, if you did the same but with cold water it would feel hot relatively.
• Locke's primary/secondary quality distinction helps explain the problems linked to direct realism as

  1. It fits with scientific understanding
  2. Accounts for perceptual variations - as secondary qualities are entirely subjective