The phrase “homo sacer” is from the Latin, and translates into English as either the "blessed" or the "cursed" man. In ancient times, this designation did have both a positive and a negative connotation, although the negative aspect outweighed the positive one. The homo sacer is an individual set apart. In classical terms, in its time of origin, the term referred to someone who was subject to certain unique rules; they did not have the same protection from harm as a regular citizen. The practice of naming these individuals, who could more generally be called pariahs, continued until the time of the implementation of habeus corpus in England in the seventeenth century.

Historians argue over whether the Magna Carta, a comprehensive legal document that provided a foundation for more modern justice systems, included the ‘seed’ of habeus corpus. Habeus corpus, a legal idea that became part of various law systems in that time, involves the banning of unlawful detention and a right to trial for those who are considered criminals. It places a broader protection over every human citizen of a nation or region, making the designation of a homo sacer rather obsolete.

In a surprising twist on this classical legal idea, some have argued that recent legal wranglings actually revive the idea of the homo sacer as undeserving of the same rights as others, when it comes to a fair trial and representation, as well as protection from immediate death. Many experts believe that the third Geneva Convention, established in the twentieth century, negates the idea of using a homo sacer defense for the death or unfair detention of an individual. This being the case, other legal experts turn their eyes to a unique situation regarding the 21st century “war on terror,” where the principle of homo sacer may be present to a certain degree in efforts to legalize certain types of detention, interrogation.

Experts who contemplate the term “unlawful combatant” in the 21st century point out that this role, as crafted by Western lawyers, re-instates some of the key aspects that applied to the classical homo sacer. The unlawful combatant, in other words, is marked as undeserving of certain rights outlined in the Geneva Convention. Resulting controversies are sure to continue, where broad disagreement over the legality of modern "prisoner of war" scenarios roils nations involved in the greater war on terror, and legal professionals argue for and against various practices, using ideas like homo sacer, the Geneva Convention, and habeus corpus as foundations.