ˌfiləˈsōfēəpəˈrenə̇s noun
Usage: sometimes capitalized both P's
Etymology: New Latin, literally, perennial philosophy
: a group of universal philosophical problems, principles, and ideas (as concepts of God, freedom, and immortality) that perennially constitutes the primary subject matter of philosophical thought : the foundations of Roman Catholic Christian principles especially as philosophically formulated by St. Thomas Aquinas and Neothomists
some Philosophia Perennis which would be agreed on in advance as a sort of intellectual base of operations — H.D.Aiken