Introduction to Epistemology

Epistemology is the study of knowledge – how we know things, what it means to know something, and the limits of what we can know. Epistemology can often seem like an abstract philosophical pursuit, but it has many important applications in underpinning our ideas about assessing evidence in science, law, politics, and elsewhere. This page contains an introduction to key concepts in epistemology, providing a basic introduction and the basis for further reading in particular topics of interest.

Newton by William Blake

Knowledge and Skepticism

What is Knowledge?

What is Skepticism?

Types of Skepticism

The Regress Argument

The Problem of the Criterion

The Evil Demon Argument

Theories of Justification






Knowledge Acquisition

A priori and a posteriori

Rationalism and empiricism

Deduction, induction, and abduction

Holism and reductionism

Scientific Knowledge

Demarcation problem


Theory dependence of observation

Occam’s razor

Paradigm shift

Scientific realism

The problem of induction

Additional Resources

Theory of Knowledge: comprehensive lecture notes for university course on epistemology

Understanding Science: An overview: great web series produced by UC Berkley

Epistemology: useful introduction

Epistemology: Internet Encyclopedia of Philosophy

What is epistemology: useful introductory article

What is philosophy of science: Scientific American article outlining the importance of philosophy of science for scientists

Epistemology: Stanford Encyclopedia of Philosophy

Epistemology resources: useful set of materials from Importance of Philosophy