This dictionary was born in 2001 as a result of a project funded by Fundação para a Ciência e a Tecnologia (POCTI / FIL / 39453/2001). The intention of its original editors and principal investigators, António Marques and Diogo Pires Aurélio, consisted in the construction of an explanatory list of the fundamental concepts of ethics, political philosophy and philosophy of law, counting on the contribution of some of the most specialized researchers of these areas in the Portuguese language. The scientific emphasis would focus on the transversality of each concept addressed to the various areas of practical philosophy, starting from a methodological perspective that embraces the need to explore various normative dimensions of the same concept. Each entry would then include a historical view of the main theories developed, as well as a presentation and discussion of contemporary perspectives, thus offering the reader both the historical genesis of the problem and the most relevant areas of debate. Once the list was completed, the online dissemination of the entries would be published in book format. As years passed and the number of entries increased, the editors soon realized that it would be impossible to reach closure since each problem requires a new entry, which in turn presents another problem requiring a new entry, and so on. What began as an online provisional dissemination of a future book became, more appropriately, a periodical publication continuously in progress.