Epistemology - Introduction to Theory of Knowledge

There is a difference between knowing and believing...

Knowledge Belief
Is true Can be false
Confident Less confidence
Good basis Any basis

Skepticism is the belief that we can never truly know anything. Skepticism has 2 schools...

  • Academic: Sensory information(empirical knowledge) is not enough to know things.
  • Pyrrhonian: Academic skeptics believed that knowledge is impossible - Pyrrhonian's questioned that too.

Biggest argument for this is the Brain in a jar argument(Basically, that we live in Matrix) - so we can't be sure about the information that our senses gives us. This is a "Global skepticism".

An example of skepticism about a range of knowledge is: What if the world was created 5 minutes ago with historical records and made up memories. How do we know that the past is true?

Single fact skepticism: possibilities that a something is missing from our knowledge. Eg. How can we look at a clock and believe that the time is 4:20? What about the possibility that the clock is broken? Or wrong?

Some solutions have been proposed...

Rene Decart

We can be sure that we think. So, "I think, therefore I exist"

Post that he goes into God territory(If I can think of an infinite and perfect being(God), that couldn't have come of an flawed mind like my own - therefore God exist) which is, well, wrong.

Bertrand Russell

Russell argues that the common sense hypothesis(that the world is real) is better because...

  • Simpler(Occam's Razor)
  • Part of our 'Instinctive beliefs' that is logical.

He says that we should have a small doubt about common sense beliefs - but we can be reasonably sure about it that it can be considered knowledge.

G E Moore

Basically, the proof of evidence falls on the skeptic - you can believe that your hand exist - its basic common sense. If someone suggest that its just a perception, its up to them to prove that the hand does not exist - you don't need to prove that the hand exists.

Hilary Putnam

He uses a Semantic Approach. He believes in Semantic Existernalism: All words come from our experience in interacting with the external world. By using the words "Brain in a vat", its implied the interaction with external world.

David Chalmers

He argues that your beliefs are true in relation to you. Even if you are a brain in a vat, the belief that you are looking at your hand is true relative to you. Your meaning for the word "hand" would be different from what a common sense world would have - but still true relative to your reality.

Even if its proved that you are a "brain in a vat", it just means that reality is weird - not that you can't believe anything.

Timothy Williamson

Defensive Approach: Critical thinking is good - but skepticism takes it too far robbing us of the resources to reason as well. If critical thinking is our immune system then skepticism is an auto immune disease.

Edmund Gettier

Justified True Belief: Someone know a Proposition only if...

  • Proposition is true
  • Subject believes(not just a hunch) the Proposition
  • Subject is justified in the belief

Gettier problem: A justified true belief that was true by luck and not competence. Eg. You check time on a broken clock exactly at the correct time that is shown on the clock.

Michael Clark

No false beliefs.

  • Proposition is true
  • Subject believes the Proposition
  • Subject is justified in the belief
  • The belief on the Proposition is based on true grounds.

The clock example is no longer a problem because you believed that the clock is working - which is not a 'true ground' for belief.

But this might be asking for too much - because you'll need perfect knowledge of all things to make any knowledge

Keith Lehrer and Thomas Paxson

Knowledge if of two types...

  • Basic Knowledge: True belief that can be justified without any supporting statements - not relying on anything else to be true.
  • Non-basic Knowledge: Requires justification. There is a hidden fact that the subject is not aware about(the clock is not working). This is called a defeater.

Alvin Goldman

Casual Theory of Knowledge: Subject know that Proposition is true if and only if the Proposition is the causally connected in an appropriate way to the belief that the proposition is true. "Appropriate Way" can be...

  • Sensory perception
  • Testimony
  • Inference

We know that Niel Armstrong landed on the moon because our knowledge came from a causal chain that went all the way to him landing on the moon(he landed on the moon > it was telivised > people wrote books about it > We read the books > we know - there is a causal chain).

Reliabilism: Subject know that Proposition is true if and only if the Proposition is formed by a reliable belief forming process.

Fred Dretske and Robert Nozick

Tracking Theory: You know the Proposition is true if and only if there...

  • If proposition is NOT true you wouldn't believe it(sensitivity requirement)
  • If proposition was true you would believe it(adherence requirement)

Closure Principle: If you have knowledge that X is true and have Knowledge that X implies Y, we can form knowledge that Y is true.

Linda Zagzebski

Knowledge First Epistemology

Earlier: Knowledge = Belief + Truth + X. Now lets figure out what X is.

Knowledge could be a basic element - something that could NOT be sub-divided. Belief came out of Knowledge - and not the other way around.

Knowledge is a State of true belief that arises out of acts of intellectual virtue(Virtue Epistemology)

Timothy Williamson

Knowledge is the most basic Factive Mental State.

All factive mental states entails knowing.

Factive: Only relate to a fact/truth Mental State: Explains our behavior as agents

Virtue Epistemology

  • Growing approach focused on intellectual character
  • Source of novel solutions to traditional problems
  • Source of normative guidance for our individual and collective intellectual lives.

It has 2 assumptions...

  1. Epistemology is a normative(how things ought to be) disciple
  2. Questions about our intellectual virtues and vices are the most fundamental questions of Epistemology.

Epistemology is to our intellect, what ethics is to our practical life. Epistemology tell us how to think where Ethics tells us how to act.

Ernest Sosa

Knowledge is true belief that is virtuously formed.

The mere possibility of massive deception is irrelevant to actual knowledge.

Robert Roberts and Jay Wood

Intellectual Virtues

  • Epistemic Humility
  • Courage
  • Caution
  • Autonomy

They are related to value ethics.

Miranda Fricker

Epistemic Injustice: Wrongs done to people specifically in their capacity as knowers and knowledge transmitters.

Virtue of Testimonial Justice: Should be able to judge a testimony without getting affected by their prejudice.


The same statement can true or false depending on the context. Eg. "Its sunny now" can be true and not true depending on the context of the current weather.

How you use the word "know" depends on the context. So we can claim to know things as long as we are not talking in a skeptical context. This is a semantic argument - its an claim about the language - and not about knowledge itself.

Keith Derose: Knowing something by Skeptic standards means that one has to be Omniscient.

John Locke: Intuition

Intuition according to different philosophers...

  • Plato: Memory of forms
  • Locke: Response to features of our ideas
  • John Austin: Grasp of Ordinary language
  • Others: An indirect way to grasp knowledge and morality

Even though Intuition is a decent test of ideas, it can be wrong too. Something that people thought is intuitively correct can turn out to be wrong when analyzed properly. Also, different people can have different Intuitions about the same thing.

If we find a problem with our intuitions...

  • Learn about cognitive biases that might be causing an incorrect intuition.
  • Defend the counter intuitive theory on the basis of theoretical virtues.
  • Train ourselves to have better intuitions in similar situations.