“The Infinite Essence has never been known to manifest in mages.” Pg. 141 1st Ed core “A 5th Essence, the Infinite, is thought to exist, but like the quark in current quantum physics, it must exist because of its apparent absence.” Pg 114 2nd Ed core
Mentioned on pg. 16 Masters of the Art.
Pg. 267 Mage20 core mentions it.
Pg. 42 of Initiates of the Art mentions Infinite Essence which is “supposed to reflect the universe itself, in the variety and balance of its many forms.”