Freshman poly-sci instructors need fret no longer, however; as an introduction to democratic principles, Robert A. Dahl's On Democracy is rather tidy, indeed. Dahl, an emeritus professor of political science at Yale, covers questions like "Where and how did democracy develop?" in accessible--almost chatty--prose, often taking the time to say a few "words about words," in which he examines, for example, the historical connotations of "democracy" and "republic" (it turns out that until James Madison declared there was a political distinction to be made, the only difference between the two was their etymological roots). Experienced readers may find their eyes glazing over at pronouncements such as "Democratic institutions are less likely to develop in a country subject to intervention by another country hostile to democracy in that country," but if you're looking for a comprehensive yet brief overview of how democracy works, On Democracy fits the bill.