The third and fourth book of Aristotle's Politics discuss fundamental questions in political philosophy: the nature of citizenship, the purpose of the state, the role of law, the merits of various constitutions. Richard Robinson's volume was the first to be published in the Clarendon Aristotle Series, and it remains a model of its kind - a lucid and provocative Introduction, an accurate but readable translation, and concise and critical notes. For this reissue, David Keyt has written a Supplementary Essay, in which he surveys and develops some recent ideas on the main themes of Politics III and IV. He also provides an up-to-date bibliography.