What is knowledge? How does it differ from mere belief? Do you need to be able to justify a claim in order to count as knowing it? Knowledge: A Very Short Introduction considers these epistemological questions alongside new puzzles arising from recent discoveries about humanity, language, and the mind. It explains the formation of major historical theories of knowledge, and shows how contemporary philosophers have developed new ways of understanding knowledge, using ideas from logic, linguistics, and psychology. Covering topics ranging from relativism and the problem of scepticism to the trustworthiness of internet sources, this VSI uses everyday examples to explain the key issues and debates.