Epistemology means the theory of knowledge. Main questions in Epistemology are...

  • What is the nature of knowledge?
  • What are the obstacles to the attainment of knowledge?
  • What can be known?
  • How does knowledge differ from belief?

How is knowledge obtained?

  • Empirisism: Knowledge can be obtained with our senses. But it can't be trusted always(eg. Optical Illusions).
  • Rationalism: Knowledge can be obtained through reasoning.

Types of Knowledge

  • Propositional Knowledge: Knowledge of facts(Eg. 3-1=2, A dog has 4 legs). This is what Epistemology traditionally focuses on.
  • Practical Knowledge: Skill/Know-how(Eg. driving).

What is Knowledge?

Knowledge is "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

Exceptions to this are called a "Gettier Case". 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.


  • Introduction to Epistemology
  • Epistemology - Introduction to Theory of Knowledge