This book investigates a number of key terms in Irish -- duchas, duthaigh, dual and saoirse -- along with a number of associated terms and derivatives in order to show how their pragmatic, semantic and syntactic range evolved over time in relation to differing historical conditions, showing what characteristic features of the Irish language and of Irish cultural attitudes, practices and experiences can be identified through this analysis. The aim of the book is to establish the affiliations between these ranges and the sometimes catastrophic changes that beset the culture in which these concepts played such a defining role. The discussion is situated within the linguistic-anthropological theories of Boas, Sapir, Whorf, Voloshinov, Pierce, Saussure and many other commentators of more recent vintage, particularly Silverstein and Wierzbecka. A word like duchas configures a whole ideology that belongs to a community and that is inflected over time by force of circumstances. The fundamental forms of that community's belief in ideas of 'right' and all the decorum of habit and practice manifest themselves grammatically in the language. Consider the 'habitual' where a decisive difference between the practices of Irish and English and their language communities is exposed and the implications considered. In a somewhat different, although related, register, the evolution of the Irish conception of freedom (e.g. the difference between cead and saoirse) is charted against the Polish and English forms of that word in order to illuminate a process in Irish historical experience.by mapping on to it a semantic and syntactical sequence of changes.