This is a question I've had for a while, as I've heard it said that the imperitives are all that matter and the essentials are somehow less important.
One interesting thing I found in the dictionary is that essential is a synonym for imperative. I have to assume that Homer knew this and intentionally and carefully selected two words that mean the same thing.
So is one less important than the other or do they just deal with different things (physics vs. geometry perhaps)?