A guide through the theory of knowledge, giving careful consideration to such issues as relativism about truth, scepticism from Descartes onwards, and the linguistic relativism of Benjamin Lee Whorf. Gives a solution to the Gettier examples and a careful overview of Hume's views on induction. The emphasis throughout is on the kinds of issues that often arise for non-philosophers when considering questions about knowledge. Thus the book is suitable for all moderately educated readers, not simply academic philosophers.