This book explores the distinction between private and public aspects in competition law and focuses on how the concept of competition is incorporated into the legal framework.Distinguishing between antitrust regulations and competition-related legal rules in private law, such as unfair competition and contract laws, the book also differentiates between the utilitarian and deontological principles that underpin competition regulation. This historical and philosophical approach is used to compare two influential jurisdictions: England and Spain. These legal systems have had a significant impact on the development of legal rules in Common law and Civilian (Latin American) countries, respectively. Through this lens, the book further analyses the concept of "competition" and its value in each legal tradition. This understanding, in turn, helps clarify the scope of competition regulation within antitrust and private law and how the two fields coexist. Additionally, the book examines the role of property law theory in the context of competition regulation.The book will be of interest to students and scholars in the field of competition law, tort law, and legal history.