Epistemology - Reason as a Source of Knowledge

A posteriori

Knowledge that requires (sense) experience to be known to be true, knowledge that is dependent upon sense experience.

What is an example of a posteriori knowledge?

Snow is white

A priori

Knowledge that doesn't require (sense) experience to be known to be true, knowledge that is independent of experience (reason alone).

What is an example of a priori knowledge?

Bachelors are unmarried

How is the distinction made between a priori and a posteriori?

How we can establish whether a claim is true or not.

Analytic propositions

Propositions that are true or false in virtue of the meanings of the words, they are true by definition. The predicate is contained within the subject.

What is an example of an analytic proposition?

Squares have four sides

What is the predicate in the proposition 'squares have four sides'?

Four sides

What is the subject in the proposition 'squares have four sides'?

Squares

Synthetic propositions

Propositions that aren't true in virtue of the meanings of the words, but in virtue of the way the world is. The predicate is not contained within the subject.

What is an example of a synthetic proposition?

The bike is red

What is the subject in the proposition 'the bike is red'?

Bike

What is the predicate in the proposition 'the bike is red'?

Red

Contingent truth

A proposition that could be true or false, it happens to be true but could have been false.

What is an example of a contingent truth?

Me revising philosophy, me being born

What is an example of a necessary truth?

2+2=4

Necessary truth

A proposition that must be true (if it is true) or must be false (if it is false), it couldn't have been otherwise

What does a posteriori knowledge tend to be?

Contingent and synthetic

Why does a posteriori knowledge tend to be contingent and synthetic?

Experience tells us how things are, not how things have to be and it gives us knowledge of particulars, not universals.

What does a priori knowledge tend to be?

Necessary and analytic

Do empiricists think that all a priori knowledge is knowledge of analytic propositions and all synthetic propositions are known a posteriori?

Yes, if a proposition is not made true through logic or meaning, then it can only be established by sense experience.

Do rationalists think that all a priori knowledge is knowledge of analytic propositions and all synthetic propositions are known a posteriori?

No, we can have a priori knowledge of synthetic propositions (through reason or innately)

Who are empiricists?

Hume and Locke

Who are rationalists?

Decartes, Plato, Leibniz

What type of knowledge is the debate of innate knowledge about?

Propositional knowledge, what we innately understand and not what we might observe an animal to instinctively do.

Innate knowledge

Knowledge that is not gained from experience, but somehow part of the in-built structure of the mind.

Is innate knowledge a priori or a posteriori?

A priori, it is not gained from experience

What is Plato's view on innate knowledge?

'Theory of the Forms'

What is the problem of universals?

The relationship between a concept and a particular instance of that concept.

What are examples of the problem of universals?

The relationship between particular triangles and the universal concept of triangle, the universal concept of beauty and particular beautiful things.

How is beauty an example of the problem of universals?

We seem to have a concept of beauty, but never witness it in its pure form, only imperfectly in different people and things. What is it that a beautiful face and beautiful sunset share?

How is a perfect circle an example of the problem of universals?

I will never experience a perfect circle and yet I can clearly conceive of this concept.

How are concepts such as numbers an example of the problem of universals?

Concepts such as numbers are eternal and unchanging while evrything I experience is fleeting and changing.

What is the 'Theory of the Forms'?

Our souls must be immortal and existed prior to our bodies and this life in a different realm / world - the world of forms. In this prior existence we apprehended the 'forms', these perfect concepts in their pure state. We have forgotten these forms, but they are in us innately and our recollection of these forms is what allows us to recognise their imperfect instances when we experience them in this life. Through the process of reasoning (doing philosophy) we can regain our perfect understanding of these concepts.

What is the 'Theory of the Forms' in summary?

Innate ideas are in us like forgotten memories (so we might not always be aware of them), we can realise these innate ideas through reason, innate ideas provide timeless truths.

What is Plato's first argument for 'Theory of the Forms'?

The slaveboy argument.

What is the slaveboy argument?

Socrates asks a slaveboy a series of questions about geometry and squares. The slaveboy, who hasn't been taught geometry, solves the problems with no teaching. By the end of the questioning, the boy was able to grasp an eternal truth about geometry / squares. He didn't gain the knowledge from experience or Socrates, so he must have recovered the answers from within his mind.

What is the slaveboy argument in SLF?

P1. The slave boy has no prior knowledge of geometry / squares.

P2. Socrates only asks questions and does not ‘teach’ the boy about squares.

P3. By the end of the questioning, the slaveboy is able to grasp an eternal truth about geometry / squares.

P4. This eternal truth was not derived from the boy’s prior experience, nor from Socrates.

C. This eternal truth must have existed innately within the boy to begin with.

What are criticisms of the slaveboy argument?

The boy says he knows it is a square so he must have some knowledge of geometry and squares. Asking questions could be teaching. The boy would be intimidated. The questions imply an answer. He was learning through the questioning.

What does Plato say about universals?

We can't derive universals from our sense experience, since our sense experience is only ever of particular instances.

How does Plato claim we understand universal concepts such as a square?

Our minds recognise the essential nature or 'form' of the square and we recognise truths about this, rather than truths about the particular square. We have an innate faculty that recognises such truths as eternal and necessary. It is this faculty that gives us genuine knowledge.

What does Plato claim about our understanding gained by the sense?

It lacks certainty (our senses can deceive us), therefore such ideas are only ever contingently true (as they only apply to this particular instance), therefore the senses can only give us beliefs and not knowledge.

What type of argument is Plato's universals argument?

Deductive

What is Plato's universals argument?

P1. The senses can only reveal particular instances.

P2. The mind can grasp perfect, universal concepts.

P3. These perfect universal concepts cannot be derived from the senses.

C. The concepts must be innate within us.

What are criticisms to Plato’s universals argument?

\-We actually can’t grasp these perfect concepts, hence the fact that we find it difficult to define abstract concepts such as truth, beauty or justice and we cannot grasp certain geometric shapes / mathematical truths.

\-Plato’s theory relies on us accepting the non-natural.

What does Plato believe to be innate?

Mathematical truths, and abstract concepts.

How does Plato believe innate ideas are in the mind?

They exist inside us like a forgotten memory and are accessed through a process of reasoning.

What are Plato's evidence / arguments for innatism?

\-Meno's slave boy - we can grasp eternal truths of which we have no prior experience.

\-Universals - we can clearly grasp universal truths and abstract concepts, despite the fact that we only ever experience imperfect instances of these things.

What are the problems with Plato's innatism?

\-Confusing memory and reason.

\-We don't clearly grasp the concepts Plato claims we do.

\-The theory relies on the non-natural (circular reasoning).

What does Decartes say the three sources of ideas can be?

Innate, those that come from outside sources, and those that are invented by me.

What does Decartes consider to be innate?

The idea of God, mathematical truths and certain principles of logic.

Was Leibniz a rationalist or empiricist?

Rationalist

What does Leibniz say on necessary truth?

The senses only give us particular instances. However many instances confirm a general truth, they aren't enough to establish its universal necessity; for it needn’t be the case that what has happened always will - let alone that it must - happen in the same way.

What are examples of cases where we might be tempted to generalise to a universal truth?

You see the sun go down and rise the next day - the sun willl rise each morning.

You let go of a stone and se it dropp - heavy objects fall towards the earth

You see a right angled triangle and, by measuring the sides see that it is the case that A^2+B^2=C^2 - on a right angled triangle the square of the hypotenuse is equal to the sum of the squares on the other two sides.

You see two apples and three pears which makes five pieces of fruit.

What are the problems with the reasoning in these generalisations from particulars to universals?

Sun - north pole, sun will die

Gravity - large gust of wind could prevent object from falling.

3 and 4 are different, it could never be that this were not the case. With one and two we may have different degrees of confidence but with 3 and 4 we have certainty.

What is Leibniz’s argument based on necessary truth?

P1. The senses only give us particular instances.

P2. A collection of instances can never show the necessity of a truth.

P3. We can grasp and prove many necessary truths (such as mathematics).

C1. Therefore the necessary truths that we grasp with our mind do not derive from the senses.

C2. The mind is the source of these necessary truths.

C3. These ideas are known innately.

What does Leibniz compare the mind to?

A block of marble with veins running through it.

What does Leibniz argue about the senses?

They are necessary for all our actual knowledge but they're not sufficient to prove it all.

What does Leibniz say is needed to trigger our awareness of the innate knowledge?

Experience

What does Leibniz list as concepts that aren't derived from experience and therefore should be classed as innate?

Unity, duration, change, action, and pleasure.

Where does Leibniz say that the concepts of unity, duration, change, action, and pleasure come from?

We gain them from an awereness of self, not from the senses.

Where does Locke and Hume and other empiricists say that the concepts of unity, duration, change, action, and pleasure come from?

Our reflective experiences about ourselves, not innate in the sense we were born with them but innate in the sense that you are the source.

What do most philosophers think nowadays about innate ideas?

The mind is not born containing fully formed ideas, but structures that may have evolved over long periods of time (similar to Leibniz).

What does Noam Chomsky argue about learning language?

We have an innate capacity to learn language. It would be impossible for any human to learn language simply on the basis of what they hear whilst growing up, if their minds didn't already possess certain innate principles.

What ideas does Leibniz believe are innate?

Truths of mathematics, logical principles, the concept of identity, concepts derived from our awareness of self (unity, substance, duration, change, action, and pleasure).

How does Leibniz believe that innate ideas are in the mind?

They are inclinations and tendencies to think at birth. Experience triggers our awareness of the innate knowledge.

What is Locke's definition of an idea?

Whatever it is that the mind can be employed about in thinking.

What are the three types of ideas according to Locke?

A complete thought, a sensation, a concept

What is an example of a complete thought?

Bananas are yellow

What is an example of a sensation?

Of yellow

What is an example of a concept?

Yellow

What is Locke's definition of innate ideas?

Thoughts printed onto the soul at the point of existence, which brings into the world with it.

What is Locke's argument from universal consent?

P1. Any innate idea, e.g. idea ‘x’ must be universally held.

P2. Children and idiots do not have an idea of ‘x’.

P3. The notion that a person could have an idea and not be aware of it doesn't make sense.

C1. 'x' is not universally held.

C2. 'x' is not innate.

What ideas does Locke use to illustrate his argument from universal consent?

Whatever is, is and It is impossible for a thing to be and not to be.

How does Locke illustrate his argument from universal consent?

He attempts to prove that babies and idiots don't have an idea of ideas that are often considered to be innate to show that no ideas are universally held.

How does Leibniz respond to Locke's universal consent argument?

Children and idiots do have these ideas, they are just not aware of them. They do employ the principle of non-contradiction in their everyday life even if they wouldn't use this language. Leibniz denies that universal consent is sufficient or necessary for an idea to be innate - if everyone smoked tobacco it wouldn't be innate (not sufficient) and God could give innate ideas to certain people / past lives (not necessary).

What is the issue with Locke's argument from universal consent?

It only undermines innate ideas if the particular theory of innate ideas was bsed on the idea of universal consent.

What is Locke's transparency of ideas argument?

We are able to perceive all the ideas our minds contain, for an idea to be 'in' the mind it must have been thought of / about at some point in the past. If you have never had an idea / thought in what sense could it be in your mind?

What is Leibniz's response to Locke's transparency of ideas argument?

The idea of taking in information subconsciously (didn't use those words). Memory shows that we can know things without being conscious of them, and retrieving them can require assistance. People can have ideas they are not aware of via subconscious perception.

What is Locke's counter to Leibniz's response to his transparency of ideas argument?

Memories are formed from sense experiences, what is unconscious must have once been conscious. In the example of subconscious perception, sense experience is still the ultimate origin of this information and therefore is a poor example to defend innatism.

What is Locke's argument 'how can we distinguish innate ideas from other ideas'?

Some innatists argue that an idea can be 'in' you but you be unaware of it, then it only becomes active later in life. Locke rejects this by saying, couldn't this be true of any idea? How can we tell which are innate and which come from experience?

What is Leibniz's response to Locke's argument 'how can we distinguish innate ideas from other ideas'?

We can tell the difference between innate ideas and those from experience. Innate ideas are necessarily true. Even though a child or idiot may not be able to know many truths about mathematics, once they understand a truth they immediately recognise that this truth has universal application.

What is Locke's over reliance on the non-natural argument?

Innatism has a tendency to involve the non-natural in order to explain the origins of these innate ideas. (Plato - realm of the forms, Decartes - God). These non-natural entities cannot be investigated by empirical methods or study of the world around us, causing more problems with innatism.

What is an issue with Locke's over reliance on the non-natural argument?

It is only a criticism of those versions of innatism that rely on the non-natural.

What are Locke's arguments for empiricism?

Tabula rasa and sense impressions and concepts.

What is Locke's tabula rasa argument for empiricism?

Blank slate, all ideas can be explained through experience so there is no need to claim we have innate ideas.

What is Locke's sense impressions and concepts argument for empiricism?

All our concepts are formed from sense experiences. We have an experience and it leaves an impression in our mind that we can remember, analyse, contemplate, recognise when we have a similar experience. We can also use these impressions to imagine new concepts / ideas.

What does Hume say is the difference between impressions and ideas?

The different degrees of force and liveliness with which they strike upon the mind and make their way into our thought or consciousness. Impressions enter with the most force and violence. They are the most lively and vivid. Ideas are the faint images of the others that the mind utilizes in thinking and reasoning.

What can you do with ideas?

Augment, Diminish, Compound, Transpose, Negate

What is the first issue with the empiricism / tabula rasa response to innatism?

Do all simple ideas come from impressions? An implication of this view is that someone without an experience of a particular colour cannot have an idea of that colour. Imagine someone born blind has their sight restored, they look at the blue sky. From this impression do they now only have a concept of this particular shade of blue? Or can they imagine other shades? The missing shade of blue - if we accept that someone could imagine the missing shade of blue then this is demonstrating that not all simple ideas do come from our impressions. Hume argues that this singular example is not sufficient to undermine the whole theory.

What are responses to the first issue with the empiricism / tabula rasa response to innatism?

The shade of blue is not in fact a simple idea but a complex one, the imagined missing shade of blue would then be made from the simple concepts of blue. However, this makes it hard to understand how we would derive the simple concept of blue as it couldn't come from any particular experience. Another response is that we cannot imagine the missing shade. This however relies on the idea that we have a 'blue in general' complex concept that is derived from combining all our particular experiences of blue. However, this would surely mean that no-one has a complete concept of blue as this would be constantly evolving every time we experience a new shade of blue.

What is the second issue with the empiricism / tabula rasa response to innatism?

Do all complex ideas / concepts relate to impressions? It seems that we can have a concept of things we have not experienced (consider an atom). Equally with abstract concepts such as justice. Also it is possible that someone else might have totally different images in their head but still have a clear concept of justice so our impressions cannot be the source of the idea.

What is the third issue with the empiricism / tabula rasa response to innatism?

Do relational concepts derive from impressions? Relational properties are those like 'being near', 'sameness', 'on top of', 'north of', 'bigger than'. If I form the concept of a cat from looking at a cat then how do I form the concept of the cat being 'on' the mat? I don't exactly experience the 'on-ness'. All that appears is the cat and the mat.

What is the fourth issue with the empiricism / tabula rasa response to innatism?

Do some concepts exist in the mind before sense impressions can be properly explained? This is the idea that there must be some structures or concepts already in place in our minds / brains which allow us to make sense of our impressions. If we were in fact a blank slate then as we experienced things it would just be an uninterrupted stream of noises, shapes, colours, tastes, etc. In order to make sense of any of this information we would have to have innate structures or architecture in the mind / brain which would allow us to categorise, order and make sense of this information. Kant argues for this with his conceptual schemes theory.

What do Leibniz, Kant, and Chomsky say in response to the empiricism / tabula rasa response to innatism?

Leibniz - we are born with innate inclinations or dispositions.
Kant - We have innate conceptual schemes that help us organise our experiences. These categories cannot come from the experiences so must be innate.
Chomsky - Our exposure to language is not sufficient to account for our ability to learn to speak. This can only be explained via an innate capacity to learn. Chomsky claims this innate capacity must be universal and is seen in all cultures.

What is intuition?

A kind of inner perception, or realisation by which one has direct non-inferential awareness of abstract objects or truth. It is the capacity to discover the truth of a claim just by thinking about it and using reason.

What are the four rules in Descartes' method for knowing the truth?

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

What did Descartes claim the only clear and distinct properties that objects possess are?

Size, shape, quantity, motion and duration.

What is radical scepticism?

Subjecting all beliefs to extreme doubt to see if there are any beliefs that cannot be doubted.

What does Descartes mean by clear?

The clarity of the idea in the mind. Whether we understand it completely, in its entirety.