This is a critical edition of Cicero's Tusculanae Disputationes, which presents in dialogue form his views on the fear of death and endurance of pain, on distress and a range of other emotions, and on the importance of virtue as the basis of the best human life. The first such edition to appear in the Oxford Classical Text series, and first new edition to appear anywhere in over forty years, it is based on the most extensive survey to date of the medieval manuscripts and a generous sampling of the humanistic copies, and on a thorough familiarity with more than fifty previous editions. Beyond the text, it incorporates both a thorough yet readable critical apparatus and an apparatus fontium et testium that gathers information on the ancient texts Cicero cites and the later authors by whom this work was cited as well as extensive references to relevant passages in Cicero's other philosophical works and to other works on ancient philosophy. The text is followed by a critical appendix that offers discussions of nearly ninety problematic passages, explaining how the editor arrived at the text he has chosen to print. The edition makes available the most reliable text to date of perhaps the most accessible of Cicero's philosophica.