IN preparing his translation of the Politics Sir Ernest Barker sought to produce a version in a modern idiom which could be used by students in a wide range of disciplines. It is a mark of his success in achieving this aim that the translation is still widely recommended almost fifty years after it was first published. However, in preparing an edition for the World’s Classics series I have taken the opportunity for some fairly drastic revision. The most notable change is the elimination of a very large number of passages where Barker expanded his translation by adding words in square brackets which did not represent anything in the Greek text but which helped to clarify what he took to be Aristotle’s meaning. While Barker’s expansions were often very helpful they made it very difficult for the reader to distinguish what was being attributed to Aristotle from what were, in effect, Barker’s own comments. I have therefore deleted Barker’s additions except in a small number of passages where it was impossible to produce an intelligible version without some addition. In many cases this has involved a substantial rewriting of the relevant passages. I have also revised many other passages to bring them closer to the Greek or toremove expressions which are no longer in current English use or which might mislead the modern reader. I have not, however, attempted any wholesale modernization of Barker’s style, which is in general elegant and intelligible. Where possible, I have tried to achieve a greater consistency in the translation of key terms.