What role does the concept of political knowledge have in democratic theory? What according to democratic theorists should the ordinary citizen know about politics? What do empirical studies about political knowledge teach us? And why should we care what people know about politics in the first place? By asking the important questions, this book offers the reader a quick yet comprehensive overview of the steps that have been taken toward understanding the concept of citizen knowledge in democratic theory over the past several decades. The book summarizes and explains the essentials of a vast body of literature while the empirical studies offer data on a number of Western democracies. Furthermore, the reader is taken through the theoretical foundations of political knowledge from Ancient Greece to modern representative democracy. Clear and concise, the book offers a cutting edge insight into our current understanding of citizen knowledge in democratic theory.