This introduction to the theory of knowledge argues for the continuing relevance of philosophical debates about knowledge by connecting them to issues of authority. The discussion takes the form of an essay in historical epistemology which treats the philosopher-politician Frnacis Bacon as its pivotal figure. This affords a non-Cartesian perspective on the transition to modern philosophy from which the distinctive configurations of the Cartesian framework can be discerned. The strategy is to use history as a route to a critical appraisal of "modernism" without embracing post-modernism,Ancient Greek discussions of knowledge from Protagoras to Epicurus via Plato and Aristotle are introduced to illustrate the sense in which modern philosophy broke with ancient tradition while being at the same time conditioned by it. The Baconian vision was of human progress achieved through the acquisition of knowledge which makes domination of nature possible. The tensions inherent in this vision and the way in which they have worked to undermine it are illustrated by refesrence to the views of Kant and Hume and by tracing their consequences.