Substance Dualism


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Substance Dualism

  1. 1. Substance Dualism
  2. 2. Rene Descartes (1596-1650) <ul><li>Minds and bodies are different entities </li></ul><ul><li>The universe is made up of mind and matter </li></ul><ul><li>Bodies are physical substances that are located in space and time and are subject to the laws of physics </li></ul><ul><li>Minds are non-extended thinking substances. </li></ul>
  3. 3. Arguments for Substance Dualism <ul><li>1. Near-death </li></ul><ul><li>experiences </li></ul><ul><li>If substance dualism is false, then my mind cannot exist independently from my body </li></ul><ul><li>My mind can exist independently from my body </li></ul><ul><li>Therefore substance dualism is true </li></ul><ul><li>This deductive argument is a valid one </li></ul><ul><li>if the premises turn out to be true. </li></ul><ul><li>The question is whether minds can exist separate from the body </li></ul><ul><li>There are many similar reports of near death experiences. </li></ul><ul><li> </li></ul>
  4. 4. However, it has been argued that... <ul><li>They are visions and hallucinations caused by the brain being starved of oxygen. </li></ul><ul><li>Or by the patient being given anaesthetic drugs like ketamin. </li></ul><ul><li>Moreover in a recent study neurologists studying NDE’s found that a patients brain known as the ‘angular gyrus’ was very active during these experiences. </li></ul><ul><li>This suggests a biological explanation for the NDE’s and not that the mind has in some way left the body. </li></ul>
  5. 5. 2. The Conceivability Argument <ul><li>‘ X’ is identical to ‘y’ </li></ul><ul><li>I believe George Bush </li></ul><ul><li>is Dan Quayle. </li></ul><ul><li>You may not believe </li></ul><ul><li>me but how can you </li></ul><ul><li>refute me. </li></ul><ul><li>Need to apply Leibniz ‘s </li></ul><ul><li>law – ‘x’ and ‘y’ are </li></ul><ul><li>identical to each other </li></ul><ul><li>only if they have all </li></ul><ul><li>all properties in common. </li></ul><ul><li>If Bush is 2 inches taller than Dan than this is enough to refute the theory and my conspiracy ideas are false. </li></ul><ul><li>If we apply this law to Descartes Substance Dualism and find one property that minds and bodies do not have we can conclude that minds and bodies are not one and the same thing. </li></ul><ul><li>1. I can conceive that I exist without a body </li></ul><ul><li>2. I cannot conceive I exist without a mind </li></ul><ul><li>Therefore </li></ul><ul><li>3. My mind is more intimately connected to me than my body, thus my mind has a property that my body lacks </li></ul><ul><li>4. If my mind has at least one different property than my body, then my mind cannot be identical to my body. </li></ul><ul><li>Therefore my mind is not identical to my body. </li></ul><ul><li>What is the problem with this argument? </li></ul>
  6. 6. Arguments Against Dualism - The problem of interaction - <ul><li>Taken it as given that there is a relationship between the mind and the body and that they both influence each other in human behaviour. According to Descartes theory it would seem impossible for the two to have any connection at all. </li></ul><ul><li>In reality is it possible to do Jedi mind tricks and move physical objects with the mind alone. </li></ul><ul><li>Watch </li></ul><ul><li> </li></ul><ul><li>In deductive form </li></ul><ul><li>1. Assume that substance dualism is true </li></ul><ul><li>2. If substance dualism is true then the mind is an immaterial, non-extended thinking substance and the body is an extended physical substance. </li></ul><ul><li>3. Immaterial non-extended substances cannot interact with extended physical substances. </li></ul><ul><li>Therefore substance dualism is false. </li></ul><ul><li>What would be a response to this problem? </li></ul><ul><li>Consider the theory of parallelism </li></ul>
  7. 7. Gilbert Ryle and the Categorical Mistake? <ul><li>Oxford Philosopher G. Ryle (1900-1976) </li></ul><ul><li>Argues dualists put the term ‘mind’ into the wrong logical category and thus commit a ‘category mistake’. </li></ul><ul><li>If I were asked by a parent to see the school and I showed them the canteen, gym, study rooms and library – They may argue that they never saw the school. They only saw aspects or instances of the school. </li></ul><ul><li>Ryle applies this idea to show how dualists attribute properties to minds that we would only normally attribute to separately existing physical things. </li></ul><ul><li>When they say something like the mind can leave the body or the mind can cause the body to move – they are really saying something like ‘Love is my best friend’. </li></ul><ul><li>Defenders of dualism can accuse Ryle of simply ‘begging the question’. </li></ul><ul><li>By insisting minds should not be classified as substances, Ryle seems to assume what he is trying to prove. </li></ul>