Routledge / NetLibrary.
Available online. (W&L subscription)
Electronic book version of second edition (2007) contains essays which outline "the lives and ideas of some of the most influential figures in Western political thought, from ancient Greece to the present day," such as Aristotle, Michel Foucault, Mohandas Gandhi, Machiavelli, Karl Marx, Thomas Paine, Jean-Jacques Rousseau, and Mary Wollstonecraft.
A link will be maintained in several locations in the library Web site, including here.