Topic 3-Reason as a source of kowledge

What is innatism?

Mind contains some ideas/ knowledge at birth, meaning knowledge does not come from experience

A priori

Independent of sense experience, through reason alone

A posteriori

via experience, derived from sense experiece

What is Plato's point of the slave boy

The boy is not learning anything new but rather recollecting what he once forgot. The knowledge is innate, waiting to be revealed by experience

Plato's Doctrine of Recollection

We exist as souls in the World of Forms where we acquire all knowledge a priori. This is forgotten at birth and recalled throughout life.

Plato's World of Forms

When forms or ideas exist in an abstract state but independent of minds in their own realm, in which they are perfect

Example of Platonic Form

A perfect triangle. No one has ever experienced the perfect triangle but we can see it in our mind, everyone has a perfect blueprint/ version in their mind

What are necessary truths

Have to be true and cannot be denied without contradiction e.g 2+2\=4 is true in all possible worlds

What is contigent

Something that could be true or false e.g the table is brown

Leibniz argument against Plato

1- We can have knowledge we are not conscious of
2- Necessary truths have to be innate
3- Innate knowledge is a disposition, an aptitude to developing certain thoughts

Locke's Tabula Rasa

born as a blank slate; life's experiences put context into your mind meaning there cannot be innate knowledge

More of Locke's replies against innatism

- Universal assent (agreement), but our difference of knowledge has come from different experiences
- Babies and 'idiots' don't understand logic
- Aren't many universal moral laws
- Too many different versions of God

Lockes agruments against innatism

1-If there is innate knowledge, it is universal
2-For an idea to be part of the mind, the person must be conscious of it
3-Therefore, innate knowledge is knowledge s knowledge that every human being is or has been conscious of
4-Children and 'idiots' do not accept the basic principles of logic
5-Therefore, these claims are not innate
6-There are no claims that are universally accepted, including by children and 'idiots'
7-Therefore, there is no innate knowledge

How does Leibniz argue unconscious knowledge exists

Logical principles are pieces of knowledge we use up all the time, even if we are not aware of them

Leibniz' main arguments for innatism

-We can have knowledge we are not conscious of
-Necessary truths have to be innate
-Innate knowledge is a disposition, an aptitude to developing certain thoughts

Lebneiz' reply to Locke's blank slate

The mind is not blank you just need experience to reveal what was already there

What is empiricism?

The theory that all knowledge is derived from sense-experience (Locke, Hume)

What is rationalism?

The belief that knowledge is gained by thinking things through using reason (Plato, Leibniz)

Hume's Fork

We can have knowledge of just two sorts of claim: the relations between ideas and matters of fact.

Relations of ideas

-Necessary
-Maths, logic, definitions
-Can be known a priori
-Do not give any significant information about the world
-Cannot be denied with contradiction

Matters of fact

-Contingent
-Statements about the world that add information to the subject
-Can beknown a posteriori
-Give information about the world
- Can be denied without contradiction

What is a tautology?

A statement that is always true by logical structure (I believe..., I think...)

Arguments for rationalism/ innate knowledge

-Maths doesn't need empirical experience
-Intuition and innate knowledge explain why we recognise morality
-Knowledge is revealed/ triggered
-We can't experience pi

Arguments for empiricism

-We see multiple/ single objects, concepts of numbers need sensory experience
-Works with empirical world, unobservable concepts
-Innate knowledge is not shown from birth

Arguments against innatism/ rationalism

-If we had innate knowledge why do we have to learn things
-Empirical truths can be discovered through senses e.g you can see when someone is in pain
-If we have innate knowledge why do we go to school

Arguments against empiricism

- How we perceive the empirical world is not how it is
-Induction makes us fall into scepticism
-We can't use our senses to recognise what is right/ wrong but can recognise

Hume's view of the mind

-No innate ideas
-The mind is passive until it receives experience and cannot generate new knowledge
-The mind is subject to some laws of nature as the brain
-Mind is constrained to what is receives from sense experience

Hume's theory of ideas

-Everything that goes on in the mind can be divided into impressions and ideas, all ideas come from earlier impressions
-Ideas are never as forceful and vivacious as the original impression
-Impressions give simple ideas, from which we can create complex ideas e.g compound (put together), transpose (move around), augment (make bigger), diminish (make smaller)

Impressions

Experience, from the senses or emotions

Ideas

thoughts, belief, memories

Relationship between impressions and ideas

All ides come from earlier impressions, ideas are never as forceful and vivacious as he original impression
Ideas copy impressions like a 'faithful mirror'

complex ideas

-Compound (put together)
-Transpose (moved around)
-Augment (make bigger)
-Diminish (make smaller)

Humes proof 1

All complex ideas can be broken down into simple ideas that are traced to impressions
God, from our experience of love, father figures, power and so on

Hume's proof 2

If someone doesn't have impressions they cannot form the idea
A blind man can have no notion of colour, a deaf man can have no notion of sound

Intuition

-The ability to understand something immediately, without the need for conscious reasoning.
-A priori
-Non-inferential knowledge

Deduction

-Premises and a certain conclusion that is inferred from the premises
-Conclusion should be certain if the premises are valid and true
-Example of how knowledge can be a priori and not innate

Descartes rotting foundation

All of his foundation was sense experience, which was faulty as you can't trust the senses, he had to destroy and rebuild his foundations

Descartes 3 waves of doubt

Senses, dreaming, deception

Descartes on senses

The senses have sometimes deceived him e.g size of a building
Never trust the senses to provide him with knowledge

Descartes on dreaming

Dreams are just as vivid, and we have sensory experience that seems just as real as waking life- you can't tell whether or not you're dreaming

Criticism of dreaming argument

-When awake we can reflect on our dreams
-When asleep we don't reflect on waking life
-Hobbes: there are conclusive signs to when we are awake and dreaming, there is an asymmetry

Descartes' Evil Demon

we know we exist, but we are not certain we have a body or senses, but we can be certain that we have thought; Descartes discredits this being because God is merciful and would not let such a being harm us; we are as we perceive ourselves.

What is the cogito?

Ego Sum, Ego Existo- I Am, I Exist
The fact that Descartes is doubting himself shows that he exists, even if he is being deceived there is something to be deceived

Cogito response to evil demon

As long as Descartes thinks he is something, although the evil demon can deceive him, he cannot cause him to be nothing
-Thoughts are essential, you are not your body but your mind/ soul

Hume's criticisms of the cogito

-Hume would say Descartes is confused
- You can't attach your thoughts to anything, there is no 'I'
-Your only experience is experience, we only know that there is a bundle of perceptions

Descartes on God

Essence and existence are two separate things. Essense is what makes something what it is e.g a triangle with 3 sides
God's essence shows that he exists, his essence includes existence this is because the definition of God is a supremely perfect being

Descartes' Ontological Argument

P1- Descartes has the clear and distinct idea of a God that is a supremely perfect being
P2-Existence is a perfection
P3- It is impossible to think of a supremely perfect being who lacks some perfection
C1-Therefore, God exists

Descartes on the external world

Descartes says that the source of his ideas is the material objects themselves.
He concludes that there is a material world that causes his ideas of objects, which he senses through the body

Descartes argument for the external world

P1- I have the ideas as if of the objects in the external world
P2- All ideas have a cause
P3- The cause could be myself, God or the external world
P4-I am not the cause of my ideas because I cannot control them- they are involuntary
P5- God is not the cause of my ideas because if he were giving me the ideas of objects that did not exist he would be a deceiver (Deceit is an imperfection)
C1-Therefore, the only possible source of my ideas is an external world that I experience through the senses