For a secret society called the Order of the Illuminati - emulating the ancient schools of wisdom, and having a "Minerval Academy" as a foundation - would there have been a more fitting symbol than the Owl of Minerva? The class of Minerval was a relatively low rank in the scheme of things. However, it was the soul of the Order, and functioned as a sort of assembly line for recruits.Candidates advanced from Novice to the Minerval degree, where they were properly vetted, scrutinized, and indoctrinated. The Quibus Licet notebooks were introduced, maintained and thoroughly kept (which eventually turned into a detailed history of yourself and those around you). You were admonished to gain wisdom from figures in ancient Greece and Rome; essays were required to pass the test; and the art of Scrutator (or Physiognomy) was elevated to a sacred science. The Minerval Superior - a Minor or Major Illuminatus - was given the code: Nosce te ipsum; Nosce alios [Know thyself; Know others].
A Minerval Academy was also known as a Church; its meetings marked on the Illuminati's calendar as sacred. To the right is the seal of the Freising Minerval Church. Instead of the letters P.M.C.V., they are replaced with S.E.M.T.: Sigil Ecclesiastic Minerva Thebes; or, "Seal of the Freising Minerval Church" (i.e. Freising's alias within the Order was Thebes). (Source: conspiracyarchive)