I note that ARRL now has "five pillars", recently up from four. But wait, there are five pillars of Islam, too. Some forms of Buddhism have ten pillars. So what's this about "pillars"?
Inquiring minds want to know how many pillars are optimum. We consult the oracle - Google - with a request to find all occurrences of "N pillars" - from "One pillar" to "twenty pillars". The following is the result -- worthy of deep contemplation.