Epistemology: Theory of Knowledge

What is Epistemology?

Epistemology seeks to explain what it means for a person to know any given sentence.
Examples of seemingly obvious knowledge:
- The sky is blue.
- I have two hands.
- CBU is in Riverside.
- Trump was a US president.
- The Pittsburgh Steelers are from Pittsburgh.

One theory suggests that to know something means to be certain.
Certainty implies the ability to rule out all other possibilities where the statement is false.
Examples:
- We can look up and confirm the sky is blue.
- We can see our hands.
- We know CBU is in Riverside, not Moreno Valley or Corona.
- We are certain that Trump was a US president, and certain that the Steelers are from Pittsburgh
Example of something we don't know:
- The millionth prime number: Since we are not certain, we don't know it.

Infallibilism requires certainty for knowledge.
The dreaming hypothesis suggests we can't be absolutely certain we're not dreaming.
We can't be 100% certain that:
- The sky is not actually red in reality.
- We didn't lose a hand in an accident and are now dreaming of having both.
The possibility of dreaming undermines certainty.
Leads to skepticism, the thesis that no one knows anything at all.

A variation of the dreaming argument.
An evil demon could be deceiving us about every aspect of reality, including:
- The color of the sky.
- Having hands.
- The existence of CBU.
- Historical and sports facts.
Examples in film that play with this idea:
- The Matrix.
- Inception.
- The Truman Show.

Even if deceived by an evil demon, the act of thinking proves existence.
\text{Cogito, ergo sum}
The very fact that you're thinking and wondering about being tricked proves that you exist.
Descartes' argument provides a single point of certainty: our own existence.

Initial assumption: We know certain things.
Skepticism: The possibility of dreaming or deception leads to the conclusion that we don't know anything.
Descartes' Rescue: We can know with certainty that we exist.

Infallibilism is too strict.
It requires too much certainty leading to radical skepticism, where virtually nothing can be known.
Common sense suggests that many things can be known, even without absolute certainty.
A milder approach to defining knowledge is needed.

Initial attempt: X is a square if it has four sides.
- Counterexample: A rectangle has four sides but isn't a square.
Second attempt: X is a square if it has four equal sides.
- Counterexample: A rhombus (diamond shape) has four equal sides but isn't a square.
Third attempt: X is a square if it has four equal sides and only right angles.
- No counterexamples can be found.
- Successful definition: A square has four equal sides and only right angles.

To know something, it must be true.
It's impossible to know something false, just as a square cannot have three sides.
Believing something false doesn't equate to knowing it.

The example of Coco and the doors vs. wheels question:
- Coco believes there are more doors than wheels in the universe, but she's just guessing.
- If she happens to be right, does she know it?
No. Correctness does not mean knowledge.
True belief isn't enough; justification is required.
You have to be justified; you have have evidence.

Not only must a belief be true, but the person must also have adequate evidence or justification for that belief.
The JTB theory of knowledge was advocated by Plato.

Scenario: You see a clock in a classroom that reads 10:10, you believe it is 10:10, and it is indeed 10:10.
You have a justified true belief.
However, the clock is broken and has been stuck at 10:10 for a month.
Do you really know the time?
Intuition: No. You are just lucky that the broken clock happens to show the correct time at that moment.
Conclusion: JTB does not equal knowledge.

Since 1963, philosophers have recognized that knowledge requires more than just JTB.
What is that fourth condition needed for knowledge?
Proposals and counterexamples to those proposals continue since the 1960s in epistemology trying to identify the fourth condition.

An alternative approach that challenges the traditional definition-seeking approach.
Analogy: Defining "crimson".
Defining Crimson
- X is crimson.
- Crimson is a deep red color.
- Is it possible to provide a full definition of crimson that distinguishes it from all other shades of red?
- It seems impossible.
Knowledge-First Concept
- Like crimson, maybe there's no full definition of knowledge.
We can identify certain characteristics of knowledge.
- It must be true.
- It must be believed.
- It must be justified.
However, there may be no exhaustive definition of what it is to know something.
Knowledge-first epistemology acknowledges the difficulty in providing a comprehensive definition for knowledge.