This volume presents the texts of James Harrington's first and last political writings, The Commonwealth of Oceana (1656) and A System of Politics (written c. 1661 and published posthumously in 1700), as they were prepared by the present editor for The Political Works of James Harrington (Cambridge University Press, 1977). The seventeenth-century spelling, punctuation and paragraph division of The Commonwealth of Oceana were modernized for that edition, as were those employed by John Toland and his printers for The Oceana and Other Works of James Harrington (1700), the edition in which A System of Politics appeared for the first time. In 1977 as now, the intention was to produce an edition for the eye of the modern reader, leaving detailed textual criticism (if thought necessary; none has been undertaken so far) to be performed upon the published originals. (No manuscripts by Harrington are known to exist.) The 1977 edition also contained an introductory and interpretative essay of 150 pages; this has been drawn upon in writing the introduction to the present volume, which is nevertheless a new piece of work.