This book examines the reason and intent behind the many Senecan and pseudo-Senecan quotations in Fernando de Rojas' masterpiece Celestina (1499), which enjoyed enormous popularity in sixteenth-century Europe. The author considers the importance attached to Senecan thought in the oral, scholarly and literary traditions of fifteenth-century Spain and demonstrates how readers' tastes and sensibilities were shaped by it. The main themes of Celestina, such as self-seeking friendship and love, pleasure and sorrow, gifts and riches, greed, suicide and death, are shown to be rooted in this intellectual background. The Senecan tradition, albeit treated in a satirical vein, is also seen as underlying the later additions and interpolations to the text, with a shift towards Seneca's tragedies in response to changes in fashion; Professor Fothergill-Payne reveals that even the Petrarchan quotations in Celestina have Senecan sources. Seneca and Celestina thus offers a fresh perspective on the literary and intellectual sources that shaped this famous book.