Epistemology

philosophy

Definition

Epistemology

Epistemology is the branch of philosophy concerned with knowledge: its nature, sources, structure, and limits. It asks what it is to know, how knowledge is acquired, what separates knowledge from mere opinion, and where justification runs out.

Formally, it studies the relation $S⊩p$ — that a subject $S$ is justified in holding the proposition $p$ — and the conditions under which $S$‘s belief counts as knowledge rather than accident or assumption.

Central Questions

Epistemology is organised around four recurring questions:

• What is knowledge? The structure of $S⊩p$ and the conditions that promote a belief to knowledge.
• How is knowledge acquired? The admissible sources — perception, testimony, reason, memory — and what each can ground.
• What are its limits? What $S$ cannot justify, and the sceptical pressure that the limits create.
• What is its structure? How justified beliefs depend on one another, and whether the structure is foundational, coherent, or inferential.

The Classical Model

The traditional analysis treats knowledge as justified true belief: $S$ knows $p$ iff $p$ is true, $S$ believes $p$, and $S$ is justified in believing $p$. This decomposes knowledge into a truth condition, a belief condition, and a justification condition. The model is the default reference point, even though it is known to fail on edge cases.

Sceptical Pressure

Epistemology and scepticism are paired: every account of $S⊩p$ must answer the sceptic who denies that any such relation reaches beyond the subject’s own mind. Solipsism is the limit case, where the set of justifiable propositions collapses to the contents $M_S$ alone.