Rationalism

• Rationalism

  Key philosopher: Descartes

  • Analytic statements
  • A priori knowledge "all bachelors are unmarried"
  • The mind has innate knowledge at birth
• Intuition


  Knowledge that appears to be based on subjective judgments or gut feelings rather than specific learning
• Rational intuition


  When you understand the claim, you see that it must be true
• Deduction


  An argument whose premises , if true, provide conclusive evidence for the truth of its conclusion
• Descartes' method, seeking the truth

  1. Accept only beliefs that can be recognised clearly and distinctly to be true
  2. Break down every problem into the smallest parts
  3. Build up every argument systematically, in the right order
  4. Carefully check to ensure no steps are left out

  This method can help Descartes write a valid philosophical argument as he can clearly set out his arguments & constantly check the validity of his methods & reasoning
• Descartes got to the conclusion "I think therefore I am" by showing that the only thing he knows exists is his mind - even his body may be a dream. He knows he is real, as he can think
• Descartes, the wax argument 


  • When I melt a piece of wax, it loses all of its original sensory qualities (e.g. taste, smell, shape) yet I believe it's the same wax
  • So, the wax is not sensory qualities
  • So, when I think of the wax, I am thinking of something that is extended & changeable

  Therefore, knowledge requires reasoned intuition
• Clear ideas

  Ideas we cannot help but notice

  E.g. Strong physical sensations such as pain or thoughts, a strong desire
• Distinct 


  Ideas you cannot possible be confused about, you know the absolute certain truth of it.

  E.g. a toothache would not be a distinct truth, but clear as you know it hurts but may not know exactly where the pain is
• Criticism of clear and distinct ideas

  Not clear and distinct enough!

  Leibniz says a more detailed account of three terms is needed to apply to the criteria of truth

  • Just feeling is not enough for truth
• Criticism of clear and distinct ideas

  Quick generalisation

  Generalises, Descartes says every belief that can be conceived clearly and distinctly must be true, is this valid? Descartes' beliefs are based on little evidence 🧾

  • What Descartes is saying is like observing a pink pig and concluding every pig 🐖 must be pink 🩷
• Criticism of clear and distinct ideas

  Only internal criteria of truth

  What makes a belief true 😉 is how it relates to the external world 🌎 outside of your head.

  E.g. belief "in the field, there are 5 cows" 🐄

  This belief is only true if it accurately corresponds with the real world 🌍
• The cogito uses A priori intuition because...

  • Descartes' came to the cogito through reason & logic, this is A priori intuition

  However, this is questionable as it is difficult to understand exactly how the cogito works just through reason, many people believe experience is needed to understand the cogito
• The Cogito could be considered a deductive argument because the premise gives the truth of the conclusion

  P1: I am thinking

  P2: if I am thinking I must exist

  C: I must exist

  However, this is questionable as some people believe the Cogito isn't deductive & needs an extra premises to be deductive

  P3: I cannot exist without thinking
• The Cogito could be considered a transcendental argument because you must think to exist, the act of doubting your existence means you must exist as you are able to think

  However, this is questionable as the Cogito cannot work simply as knowledge that people just know, it may need to be more clear and distinct to count as transcendental
• The cogito is arguably self-verifying as the Cogito is verified when you are thinking which means you exist (according to the cogito) Verifies the Cogito and so verifies you exist
• It is questionable whether the Cogito is actually self verifying as it is uncertain whether this point has been made as an intuition or only as a deduction involving stages
• Synthetic


  A truth that cannot be known though the sentence alone. experience/sense-data is required to verify the statement
• Russel disagrees that Descartes has produced A priori knowledge due to his "different thinkers" argument

  Russel's issue with "I" by Descartes is that he is saying our entire existence is just "I", there our many things that make us human, Descartes believes we are just a brain but Russel argues we are much more than that. "I" does not prove the self as he believes the qualities of being a human are much more than that.
• Hume disagrees that Descartes has proven A priori knowledge due to his "no meaningful self just a bundle of thoughts argument"

  Hume says that perceptions prove our existence as we exist when we are feeling, e.g we exist when we feel love. Perceptions must be part of our self - not just thinking, we cannot do anything if we are not perceiving some way.
• Stroud disagrees that Descartes has produced A priori knowledge with his "no thinker at all argument"

  Stroud disagrees with Descartes as because Descartes is skeptic about anything other than the mind existing, how can we prove we exist because we think?

  "It may be obvious you need to exist in order to think, or to doubt, but maybe you don't?"
• Descartes has overall not proven A priori is the only source of knowledge needed, although we can discover some facts through reason, much of our knowledge requires experiences. For example, Hume proves we need perceptions of sensual experiences to even think - therefore, we cannot think without experience.
• Trademark


  Descartes argues the concept of God is innate like a "trademark" that our creator has stamped in our minds
• Substance


  Something that can exist independently
• Attribute


  A property of a substance
• Mode


  A particular determination of a property
• Descartes' trademark argument is used to prove the existence of God. He argues the concept of God is innate, as God has put the concept there, like a trademark. God has placed the idea of God in our minds so we innately know he exists. Descartes argues we can't of invented the idea of God and it's not derived from sense experience, so by elimination the concept of God must be innate, built into our minds by God.
• Trademark argument

  P1: The concept of God must have as much reality as what the concept is of

  P2: Therefore, my mind could not of created it

  P3: The only possible cause is God

  C: God must exist
• A substance has more reality than an attribute because an attribute (property) cannot exist without the substance, the attribute is dependent on the substance existing to exist itself
• Medieval ideas of metaphysics:

  1. A "substance" is something that can exist independently e.g. the mind, God and physical objects
  2. An "attribute" is a property of a substance e.g. the attribute of the mind is thinking
  3. A "Mode" is a determination of the property e.g. ideas are models of the mind, specific ways of thinking
• The problem with the trademark argument is that it relies on the assumption that if we have a clear and distinct perception then it must be true. However, this isn’t necessarily the case. We may perceive things clearly but they still might not be true. For example, when we dream we often think very vividly about things which aren’t real. So just because we have a clear and distinct perception doesn’t mean it’s true or even accurate.
• Criticisms of Descartes' trademark argument

  Understanding infinity

  • God's substance is infinite
  • How can we have an idea of something not within our understanding or and idea within our mind
  • Infinity is definable, not necessarily understandable
  • I cannot have an idea, there is no innate knowledge and god did not leave a trademark

  If God had left a trademark in our minds why can't we understand him?Why would he leave a trademark we can't understand?
• Criticism 2 of Descartes' trademark argument

  Causal principle

  • Cause and effect have to be balanced, once can't have more than another
  • You cannot get more out of an effect than what was in the cause. According to thermodynamics, the amount if energy remains the same in the universe, this agrees with Descartes' causal principle. However, there are many examples that contradict this idea. E.g a match (cause) makes a huge explosion (effect) So therefore, it is not clear how the physical cause of the idea must be greater than the idea itself
• Criticism three of Descartes' trademark argument

  The idea of God doesn't make sense

  
  

  There is a paradox of God being described as all powerful. Why are there things God cannot do if he is all powerful? E.g, God is unable to commit the sin of killing but he is all powerful so surely he should be able to - but he can't?

  This challenges God's omnipotence as he should be able to do everything if he is all powerful, but he cant
• The 4th criticism of Descartes' trademark argument is that the concept of God is not universal

  The idea of God cannot be universal or everyone would conceive God as omnipotent - this is not the case. So, Descartes cannot say God planted the idea of him in our mind. Furthermore, it wasn't until 500BCE in Palestine people began to think about God, so God was not discovered through experience
• Paradox


  A contradictory statement in philosophy
• Universal


  An idea that applies to anyone, regardless of cultural differences
• contingent


  Dependent upon something else as the cause of its existence. Possible for it to exist and not exist
• Necessary being


  Not dependent on anything for its existence. The being has always existed and always will do (Christian God) thus, it has to exist
• Descartes' cosmological argument

  P1: If I caused myself to exist i would give myself all perfections

  P2: I do not have all perfections

  C1: Therefore, I am not the cause of my existence

  P3: A lifespan is composed of independent parts, such that my existence one time does not entail or cause my existence later

  P4: Therefore, some cause is needed to keep me in existence

  P5: My existence is not uncaused

  P6: I do not have the power to cause my continued existence through time

  C3: Therefore, I depend on someone else to exist