This book examines the conceptual contributions of constituent representatives in Spain during the nineteenth and twentieth centuries. The Spanish Parliament has been the stage for the political modernisation of the country. Constitutional debates have historically led to the gradual acknowledgement and broadening – usually unevenly – of citizens’ rights. At the same time, constitutional debates have created opportunities to design institutions and settle legal mechanisms to enforce rights and distribute state resources. The book identifies and analyses rhetorical and conceptual innovations produced in such debates from a historical perspective.