This chapter defines the terms used throughout the book to analyse prevalent patterns in literature, thought and visual art in Ancient Greece (eighth to fourth centuries bce) and corelate them with the contemporary economic and political situation. Aggregation is defined as a paratactic sequence or assemblage of otherwise unrelated items. Antithesis is defined as the symmetrical representation of opposites. Antithesis is subdivided into antagonistic or peaceful, balanced or unbalanced, focused or unfocused. These are the central terms for this book. A further category, of less importance for this purpose, is asymmetrical opposition, which is subdivided into antagonistic and balanced or antagonistic and unbalanced or non-antagonistic.