Doubting the Senses
Can you complete the following sentence...
For Plato our senses can/cannot be trusted because...
How do you think this lesson links with maths?
We are going to be examining the philosopher Descartes.
Descartes made many notable contributions to maths; a theory of applying algebra to geometric problems (on the photo behind this text).
He was also the first to use symbols to represent powers.
He was described as a mathematical genius as well as a renowned philosopher.
Consider the following..
Have you ever woken up from a dream and had a hard time figuring out if you were awake or dreaming?
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The dream felt so real, and now you're a little confused.
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You take a couple of deep breaths, and yep, you're awake and not dreaming.
How do you know this is true?
Are you really here?
You know you are not dreaming because you can move your body however you want and you can feel your bed.
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If you were Rene Descartes, you would use your senses and your mind to prove that you are really here.
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Let's take a look at who Descartes was and his philosophy.
Descartes
Descartes pondered the same qustions as the film Inception makes us ask. How do you know you are really here?
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Descartes argued that we can not know whether or not we are dreaming.
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Descartes wanted to find something that you could know was real beyond any doubt.
Scepticism
Descartes tried to doubt everything, even those things that appeared obvious.
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His aim was to find something we could be 100% certain of.
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Descartes noted that senses sometimes deceived us.
Inception
Inception is about a thief who possesses the power to enter into the dreams of others.
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Dom Cobb (Leonardo DiCaprio) does not steal things, he steals ideas.
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By projecting himself deep into the dreams of his targets, he can steal information.
Descartes
Descartes decided that there was something he could be certain of existing...
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"I think, therefore I am" - Descartes
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What do you think Descartes meant by this statement?
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Rationalism
Another branch of philosophy.
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Rationalism: based on reason rather than evidence of experience as the basis of our knowledge.
Why would we describe Descartes as a rationalist?
Give at least 2 reasons for your answer.
Cobb
"Dreams feel real whilst we are in them. It is only when we wake up that we realise something was actually strange" Cobb
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How do you know when you are dreaming and when you are awake?
Describe at least two different ways.
Doubt
If we doubt and question the existence of absolutely everything in our world, what is the ONE thing you would be the most sure of existing and why?
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Give at least one detailed reason why you are so sure this ONE thing exists.
Descartes
Meaning
He had found an unshakeable truth the no doubt could attack...
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He EXISTED, since it was he that was thinking and doubting everything.
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CHALLENGE (Optional):
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Write down two problems that you can see with his theory that HE found proof HE existed.
Reflective
Questions
Reasonable?
What do you think of Descartes' answer to whether or not he exists?
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Do you think it is reasonable or not?
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Give at least two detailed resons for your answer.
Dreaming?
Write down whether or not this world is a dream.
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REMMEBER to write down why you think this in detail.
Extension
Ask between 3 to 5 different people whether or not they agree with Descartes' 'proof' that he exists and is not dreaming.
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Write down their answers, including their reasoning why.