Modern interpretations of the late Roman Republic have been dominated by the twin concepts of 'populares' and 'optimates', commonly assumed to refer to two antithetical political categories. However, the definition of these groups is much debated: some historians see them as ideological movements or traditions, others as differences of political style and method. This book asks whether this debate may in fact be chasing a mirage. Through a detailed analysis of the usage of the two terms in Cicero and his close contemporaries, it is argued that they carried no clear political meaning. What emerges instead is a political language focused on the elite's fundamental concerns about internal divisions and the maintenance of aristocratic consensus.