Ser Arthur Dayne was a knight of House Dayne who bore the title of "Sword of the Morning" as he possessed the ancestral sword of House Dayne, Dawn. He was also a member of the Kingsguard under King Aerys II Targaryen.
The Sword of the Morning is a title bestowed upon the knight of House Dayne that bears Dawn, the ancestral longsword of the family. The title is not hereditary, automatically passed down to the current head of House Dayne. Rather, the sword Dawn is only held by a member of House Dayne who is considered worthy of the honor, after displaying immense skill at swordsmanship. Sometimes the head of House Dayne wields Dawn, but in some generations of the family it is held by a younger brother or cousin. In some generations, no member of the family is allowed to wield the sword at all, because it is deemed that none have proven themselves worthy. When a current "Sword of the Morning" dies, he does not pass Dawn down to his own children: instead it is brought back to Starfall castle, to wait for a new "Sword of the Morning" to rise again (which may take generations).
According to George R.R. Martin, the sword Dawn remains at Starfall during the War of the Five Kings, because no new Sword of the Morning has yet risen since Arthur Dayne died.
Although the books get into the idea of House Dayne having/bestowing the Greatsword "Dawn" slightly better, the TV show still touches on Dawn, Arthur Dayne (Tower of Joy Sequence), and/or the title: Sword of the Morning, but neither the books or tv series seems to explain what the SPECIFIC conditions are for the passing of this sword. Only to say that it goes to one that is "deemed worthy" of it.
But whom specifically at Starfall or Members House Dayne gets to decide what "worthy" means, but more importantly, what is the criteria for worthiness?
To Better Understand My Question:
I'm interested in the philosophy and methodology of philosophy of House Dayne's inter-workings to help determine WHY this ritual has been preserved. Is there a council or a title given to those that decide whom and perhaps "when" someone is worthy of Dawn? Is Magic (visions) in conjunction to Religion (a belief in some desired outcome) used in this determination? Is there some kind of "test" or "long term" intent for the role of Sword of the Morning(s)?
Is there any specific instance I either overlooked or exists in other source materials to better understand these things. Any Help would be much appreciated, as I believe that
A: It enriches the story by adding to overall ASoIF/GOT philosophy.This then also helps establish themes.
B: Enhances the mythology/metaphysics ---> White Walkers, Cycle Cosmology, Reincarnation, Dawn Age/Age of Heroes & Biblical Allegory: Sword of the Morning + Starfell + Dawn = "Morning Star", The Dawn of a New Era) and *could provide a future "plot twist".