(noun) The inherent nature of a thing or idea.
"The energy of the mind is the essence of life."
"The Essence of Knowledge is, having it, to use it."
"The rose's rarest essence lives in the thorns."
"The real glory is being knocked to your knees and then coming back. That's real glory. That's the essence of it."
"Every act of rebellion expresses a nostalgia for innocence and an appeal to the essence of being."