A mage that has attained the power and knowledge to reach a higher level. It is not clear if Oracles reach their position on their own or if other Oracles accept them into their ranks. Oracles are so distant and seldom encountered that some (or many) mages believe they don’t exist. The first 2 editions of Mage state Oracles are near Ascension. 1st Edition core book pg. 36 states Oracles have 9 Chantries (or houses), one for each Sphere. These Chantries are deep in the Umbra & hard to find. A mage who wants to become a Postulant must choose a Sphere and find that Chantry. Rumors among Tradition mages claim an Oracle must die or reach Ascension before another mage can enter their ranks. 1st Edition claims Oracles visit mage Chantries to explain strange events or request services but they usually send a Postulant in their place. 2nd Edition core book pg. 47 claims some beings in the Umbra claim to be Oracles but they may be lying mages, spirits or other things. Mages generally agree that Oracles leave their former group & consider themselves above the concerns of the Council of Nine, Technocracy, etc.
Mage Modern defined Oracles on pg. 56 of Masters of the Art. It states an Oracle is a mage that reached Arete 8 or higher and chose to turn away from Ascension in order to help other mages reach Ascension. This is stealing a page from Buddhism so it’s no wonder Oracles are called bodhisattvas. Oracles started out being mages with high Arete who left their factions to pursue Ascension. In Mage Modern Oracles reached Ascension or stopped short of it to help others. This brings Buddhism into Mage in a weird way.
An Arcane over 5 makes a lot of sense for Oracles. Also, it seems fitting that just as Sleepers think mages are Sleepers, mages would assume Oracles they meet are other mages on their level.