What is Epistemology?

  • Epistemology is the branch of philosophy concerned with knowledge and the nature, sources, and limits of knowledge.

Branches of Epistemology

  • There are several key branches within epistemology, including rationalism, empiricism, and scepticism.


  • Rationalism holds that reason is the primary source and test of knowledge.
  • Key figures include Descartes and Kant, who asserted that there are certain truths which we know independently of our experiences.


  • Empiricism maintains that experience is the main source of knowledge.
  • Key account holders include Locke and Hume, who asserted that all knowledge derives from our senses.


  • Scepticism challenges the possibility of complete and accurate knowledge, sometimes denying its existence altogether.
  • A common form of scepticism is global scepticism, which doubts that any knowledge can be had at all.

Key Concepts in Epistemology

  • Some key concepts in epistemology include justification, belief, truth, and knowledge.


  • Justification refers to the logical grounding of a belief, which is necessary for the belief to be considered knowledge.


  • Belief is the mental attitude that some proposition is the case regardless of whether it is or not.


  • Truth refers to the quality or state of being in accordance with fact or reality.


  • Knowledge generally refers to an understanding of something, where ‘understanding’ means a justified true belief in that thing.

Challenges in Epistemology

  • A famous problem in epistemology is the Gettier problem, which challenges the traditional concept of knowledge.
  • The Gettier problem comprises several scenarios or Gettier cases where someone has a belief that is justified and true, but it seems wrong to say that they have knowledge.
  • This suggests there may be more to knowledge than just being a justified true belief.

Responses to the Gettier Problem

  • Various solutions have been proposed to solve the Gettier problem.
  • These include redefining knowledge, adding extra conditions to the old definition of knowledge, or accepting that sometimes knowledge does include justified true beliefs that aren’t knowledge.
  • Some theorists suggest that knowledge requires that the belief is produced by a reliable method.
  • Others have proposed the No False Lemmas response, which adds the condition that the justified true belief doesn’t rely on any false information.