This new translation makes one of the most important texts in ancient philosophy freshly available to modern readers. Cicero was an intelligent and well-educated amateur philosopher, and in this work he presents the major ethical theories of his time in a way designed to get the reader philosophically engaged in the important debates. Raphael Woolf's translation does justice to Cicero's argumentative vigor as well as to the philosophical ideas involved, while Julia Annas' introduction and notes provide a clear and accessible explanation of the philosophical context of the work.