Inheritance Cycle/Culture/Ancient Language

The Ancient Language was once a language of all beings in Alagaësia, but was later used only by the elves and some human, along with the dwarves with one moment being the crowning of their king. It was the language of the Grey Folk but then, somehow, they managed to tie their language with magic. It was used to command and regulate magic. Each act of magic was linked to a specific word: therefore, it was generally true that the more knowledge one had of the Ancient Language, the more magic they could perform. It was also possible for experienced Magic user to utilize Non-verbal manipulation, although this was extremely dangerous, if the mind wandered the spell would change. For example if a magician cast non-verbally, for example 'Burn that door', and focused on something other than the door, they may accidentally burn that instead.

It was impossible to lie in the Ancient Language because words spoken in the language were unquestionably true-although, it was said that the elves were masters at saying one thing and meaning another (for example, the swordsmith, Rhunön, said she would never make another weapon but made one through Eragon). Because of the candid nature of the language, oaths of allegiance and similar contracts were usually conducted in it, ensuring they would not be broken, though they could be twisted to be ineffective if the one who made the oath left enough loopholes in their wording.

Names in the Ancient Language were "true name" and the knowledge of such a title was a source of power and control. The same holds true of the name of the Ancient Language itself: the knowledge of the name allows one to change the meaning of its words. The name was found by Galbatorix and subsequently used against him in the final confrontation with him.

Translations
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 * Translations.