I don't think they have a motto... Now symbolism on the other hand, they have a lot of. You might recognize the hand signal most rock stars use, or what spiderman did to shoot out his webs. They use that because it mimics the baphomet which is where you get your devil worship. It's the hand sign meaning the devil. As is "As above, as below" also taken from the baphomet and the Egyptian glyphs. So there is some relation to ancient Egyptian religion and pagan religion. Pyramid of course also comes from Egypt since everyone is well aware that the pyramids were built in Egypt. The eye is Horus, or the All Seeing Eye. Yet I still believe they originated somewhere in ancient Rome. The word Illuminati is Latin for "Enlightened".