Intuition and Deduction Thesis (rationalism)

What is the definition of rationalism/intuition and deduction thesis

Rationalism: the idea that there is some synthetic a priori knowledge, gained through reason that is not innate

Intuition and Deduction thesis: We can gain synthetic a priori knowledge through reason alone, through two operations of the mind: we can come to an intuition, which is the concept of a clear and distinct idea formed by an attentive mind, without the senses, or through deduction to infer further propositions with certainty.

What is the difference between intuition and deduction

-Intuition: the indubitable conception of a clear and attentive mind which proceeds solely from the light of reason

-Deduction: the inference of something as following necessarily from some other propositions which are known with certainty (example: my kitchen cupboard is empty, leads to the deduction that there is no cereal in the kitchen cupboard.)

-The difference: Intuition refers to something that is immediate and self-evident, while deduction refers to something that occurs over time as a result of reasoning from known truths to new truths.

What are clear and distinct ideas (Descartes)

-Concepts or beliefs for which reasonable doubt is impossible because a: its truth is obvious to an attentive mind and b: any concepts not belonging to it are excluded from it

-Developed explanation in case confused:

• Clear: present and obvious to the mind

• Distinct: precisely separated from other ideas without ambiguity

What is an a priori intuition

-A belief which is 1: non-inferentially justified (do not infer an intuition from something else you believe) and 2: justified without the need for experience. For example Descartes Cogitio (I think, therefore I am)

What is the cogito

-One’s knowledge of one’s own existence, - ‘i am, i exist’. An a priori intuition which is the foundation of one’s other knowledge and its undoubtable.

-The Cogito as intuition

• When reflecting on our ability to think it is immediately evident (intuition) that in order to think there certainly must exist a thinker (that being us)

-The Cogito as deduction:

• P1: I am thinking

• P2: All thinking requires a thinker

• P3: Thinkers exist

• C: Therefore, I exist

• Can be seen as a logical inference

-Relevance:

• This becomes the foundation for knowledge as it is the first ‘indubitable truth’

-The Cogito as a clear and distinct idea:

• You cannot doubt that you are thinking, to do so would be to think (clear)

• It is impossible to confuse the concept of thinking and not existing (distinct)

How do Empiricists respond to Descartes Cogito

1: The Cogito only proves present experience, not a substantiated self

• Descartes: I can think, I know that I exist as a thinking thing

• Hume argues you only know the thoughts that are occurring now, you cannot necessarily know that there is a permanent self or soul behind them (you could be perceived about every memory you have for every moment of time you have existed)

• Alternatively, there could be a different thinker thinking every thought ( when I see the colour red, the only thing I can be certain of is that the colour red is being seen, not that ‘I am seeing the colour red’

2: Hume’s bundle theory

• When internally reflecting we can never identify a perceptual experience that relates to the concept of self

• We experience thoughts, feelings, and sensations but never a separate and enduring self

• The cogito can prove that thinking exists, but not that a thinker exists

• ATTACKS: Descartes move to ‘I exist as a thinking substance’

• Rather he could say: there are thoughts, therefore, thoughts exist

How would Descartes respond to criticisms of the Cogito

Descartes response:

• It is impossible for a thought to not have a thinker

• You cannot have doubt, willing, or imagining without something doing those activities

• The same way running requires a runner, thinking requires a thinker

• The Cogito is proof that both thoughts and the self (subject of thought) exists

Hume’s reply:

• Begging the Question: when an arguments premise assumes the truth of the conclusion rather than proving it

• Descartes assumes the existence of a substantial self in order to prove the existence of the substantial self

• Instead of proving that the self exists, he has built the self into the premise from the start (the idea that a thought requires a thinker)

• Running analogy response: mental events are different from physical events in that they may be able to simply occur without a separate self substance behind them.

• If Descartes doubts everything, it is perfectly rational/coherent for him to doubt the existence of the thinker

• He could claim ‘there are thoughts, therefore thoughts exist.

How does Descartes use clear and distinct ideas to build on the cogito and what are the criticisms

-Building from the Cogito:

• P1: The Cogito is certain (indubitably true)

• P2: The Cogito is a clear and distinct idea

• C: Therefore, any idea I have that is clear and distinct must also be indubitably true

-Issues:

• 1: Descartes generalises the truth of one clear and distinct idea to validate the claim that all clear and distinct ideas are true (fallacy of overextension: broad, universal conclusion is reached from a too-small or unrepresentative sample size)

• 2: The criteria for truth is entirely internal,

  • this contradicts with the correspondence theory of truth (a belief must correspond with fact in order for it to be true), which is widely accepted logic.

  • Football analogy: in order to know whether a goal went in you cannot just internally consider the skill of the kick, you must also see if it actually went in.

  • This risks making truth subjective and falling to the issue of illusions and hallucinations

What is Descartes proof of the existence of God

-Trademark argument

• P1: The cause of anything must be at least as perfect as its effect

• P2: My ideas must be caused by something

• P3: I am an imperfect being

• P4: I have the idea of God, which is that of the perfect being

• C1: Therefore, I cannot be the cause of my idea of God

• P5: Only a perfect being (God) can be the cause of my idea of God

• C2: Therefore, God is causing my ideas

• C3: Therefore, God must exist

-Explain:

• Goal: proving God exists, because God is perfect and does not deceive us and so it allows Descartes to trust his clear and distinct ideas.

• Acknowledges he has the idea of an infinite, all-knowing, all-powerful being

• Causal adequacy principle means that somethings cause must be at least as great as its effect (Something imperfect cannot cause something perfect)

• Descartes considers himself limited and finite, and so he is unable to be the cause of his idea of God (unlimited and infinite)

• The only thing that can cause the perfect idea of God is something just as perfect if not more (this being is God)

• God places the idea of perfection in our mind the same way a craftsman leaves a mark on his creation

How does the existence of God support Descartes claims about knowledge

-Descartes claims that the existence of God is able to bridge the generalisation gap and guarantee objective truth

-God needs to be real for Descartes theory otherwise we cannot be certain that our external clear and distinct ideas are a result of deceit, however God is omnibenevolent and would not be a deceiver

How do Empiricists respond to Descartes argument for the existence of God

-Descartes proof relies upon unjustified assumptions and ideas that are not grounded in experience

-Locke argues that we do not need God to explain the idea of perfection

• We can experience finite qualities such as wisdom power and goodness, and mentally enlarge them (the idea of imperfect human knowledge can be enlarged to create the idea of unlimited knowledge)

  • While do not have the experience of having perfect knowledge we can use our imperfect knowledge to imagine it

• The idea of God is constructed from experience not imposed on us

-Hume rejects the causal adequacy principle

• We can imagine things greater than ourselves such as unicorns, perfect islands, and fictional beings without them actually existing in the world

• Why should a perfect idea require and equally perfect cause

• Having the idea of perfection does not prove the existence of a perfect being

How can Descartes respond to criticisms of his trade mark argument

Descartes response to Locke:

• Infinity comes before fortitude

• We only recognise ourselves as limited and imperfect due to our ability to compare ourselves with that which is unlimited and perfect

• You cannot know something is imperfect if you do not have a prior standard of perfection.

• The idea of God cannot be built by finite experience, it has to come from God

COUNTER:

• Locke argues that this is not true, we understand our existence through ordinary experience and negate this to imagine ideas of perfection

• Our finite experience is negated to understand the concept of an infinite experience

Descartes response to Hume:

• The idea of infinite perfection is qualitatively different to having ordinary fictional ideas such as that of a dragon

• Ordinary fictional ‘perfect’ ideas are combinations of imperfect things that already exist (dragon = snake, wings, fire)

• We cannot gain our idea of an infinite being by combining multiple finite beings

• The cause of an actually infinite idea must formally contain that perfection

COUNTER:

• This is just assertation, what is it about an ‘infinite perfection’ that makes it any different from an ‘ordinary fictional idea’

• The mind can simply combine, exaggerate or negate imperfect or finite qualities without needing a matching cause

• The argument is dependent upon an unproven rationalist principle

What is Descartes proof of the external world

OUTLINE

• P1: Ideas pop into my head against my will

• P2: The thing producing these ideas must be outside of me and not my will

• P3: There are two options: the substance outside of me exists either in God or in an external world

• P4: My inclinations tell me it is an external world

• P5: God does not deceive me about my inclinations

• C: Therefore, ideas from perception come from an external world

EXPLAIN:

• Necessity: needs to prove that sensory beliefs can be reliable and that an external world exists in order to combat scepticism and his three waves of doubt

• Foundation: the cogito provides certainty of ourself as a thinking thing, but we do not have certainty of anything outside of our ability to think

• In order to justify trusting his clear and distinct ideas he argues that God is real and as a perfect being he is not a deceiver

• Descartes notes we are able to have vivid sensory experiences that come from an external source

• Our natural inclinations strongly believe in physical objects and an real, physical external world

• If God is the cause of our ideas and he is not a deceiver, and our ideas are that the source of our sensations exist in a real physical world, then this must be the truth

• God would not allow us to be constantly deceived about the cause of our sensations.

How does Descartes proof of the external world support his claims about knowledge

-Final step in Descartes attempt to rebuild knowledge from scepticism

-Our senses are generally trustworthy when used carefully, though not perfectly reliable, our inclinations that there exists an external physical world which is the cause of our perception is accurate

How does Empiricism respond to Descartes proof of the external world

Locke:

• Knowledge of the world begins with sensation, not rational deduction

• We experience the impressions of colours, sounds, touch, and physical resistance which then helps us form ideas about external objects and the world

• We do not need proof of God to trust our ordinary experience,

• Hume: we naturally believe in the external world due to the vivid and forceful nature of our impressions and our experience then creates habits of expectation.

• Descartes makes knowledge too indirect

• Occam’s razor: when faced with multiple explanations for the same thing, the one requiring the fewest assumptions is usually correct

How does Descartes respond to criticisms about his proof of the external world.

-Descartes:

• We are able to be deceived by our senses (Waves 1 and 2 of doubt)

• Sensory experience on its own cannot provide certainty of our knowledge about the external world

• For knowledge to be certain it must be grounded in reason and therefore rationalism

• God is needed to defeat radical doubt that arises from local scepticism (wave 3)

• Habit may explain why we believe, but it does not justify the belief (infallibilism)

-Counter:

• Occasional sensory mistakes are not a reasonable foundation for global scepticism

• This is because they can be explained (illusions: relational properties, hallucinations: mental states)

• Additionally we are able to correct bad perceptions through repeated observation and sense comparison.

• Fallible senses are better foundations that speculative proofs of God, demands for certainty are unrealistic

How can Hume’s Fork be used to counter Descartes claims about knowledge

-Hume’s Fork:

• Relations of Ideas: Necessarily true (true in every possible world), A priori (not gained through experience) , Analytic (truth contained in the definition and meaning of the words) propositions

• Matters of Fact: Contingently true (does not have to be true in every possible world, but is true in this one), a posteriori (gained through sense experience) synthetic (truth dependent on the state of the world and reality)

-Attack on Descartes:

• Descartes attempts to make a synthetic a priori claim about Gods existence due to the fact he attempts to deduce Gods existence through reason

• However, Hume argues that any existence claim about the world has to be a matter of fact ( a posteriori synthetic claim)

• Descartes also attempts to use this synthetic a priori claim to deduce another about the existence of the external world

• Again, Hume argues that any claim about the existence of the external world must be grounded in experience, it cannot be known with certainty through reason alone

How does Descartes respond to Humes Fork

Descartes:

• Humes fork is too restrictive

• Some truths such as the cogito and God are grasped by clear and distinct intellectual intuitions, not experience

• They are not merely definitions but rational insights into reality

• Hume’s fork is incorrect as claims can go beyond relations of ideas or maters of fact

Hume:

• Metaphysical claims are not the same as mathematical truths

• They are doing two completely different things: metaphysical claims are contingent hypothesis, while mathematical claims have the ability to be necessary and are able to have empirical proof

• You are unable to define something (God or the world) into existence.

• Just because a concept is clear and distinct does not automatically give it real meaning and existence.

What is the Cartesian circle

-Argument that Descartes intuition and deduction thesis is guilty of committing the logical fallacy of circular reasoning/begging the question (premise of an argument assumes the conclusion is true, rather than providing supportive evidence)

-Descartes uses his theory of clear and distinct ideas to prove the existence of God

-But he also uses the existence of God to guarantee trust in the truth of clear and distinct ideas/reasoning

-The proof is not secure as it is circular

How does Descartes respond to the issue of the Cartesian circle.

Descartes:

• Immediate clear and distinct truths such as the cogito are self-evident without God

• Gods existence provides continued trust in these truths when we are not directly attending to them, and anything we build upon immediate intuitions

COUNTER:

• This still relies on reason to validate reason, even if the circle is ‘softened’

• The proof is still epistemically unstable.