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? How can we know that the outer world is real and not a dream?

Questions like these are ancient ones, and the branch of philosophy dedicated to answering them - epistemology - has been active for thousands of years. In this thought-provoking Very Short Introduction, Jennifer Nagel considers these classic questions alongside new puzzles arising from recent discoveries about humanity, language, and the mind. Nagel 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, Nagel examines how progress has been made in understanding knowledge, using everyday examples to explain the key issues and debates.

什么是知识？它与单纯的信念有什么不同？你是否需要能够证明一个主张的合理性，才能算得上是知道它？我们怎么能知道外部世界是真实的而不是一个梦？

诸如此类的问题都是古老的问题，而致力于回答这些问题的哲学分支--认识论--已经活跃了数千年之久。在这本发人深省的《非常简短的介绍》中，詹妮弗-纳格尔在考虑这些经典问题的同时，还考虑了最近关于人类、语言和心灵的发现所产生的新难题。纳格尔解释了主要历史知识理论的形成，并展示了当代哲学家如何利用逻辑学、语言学和心理学的观点，开发出理解知识的新方法。涵盖了从相对主义和怀疑论问题到互联网来源的可信度等主题，纳格尔研究了在理解知识方面取得的进展，使用日常的例子来解释关键问题和争论。