The greatest power on earth is the magnificent power we all possess. The power of the human brain.'This is a popular quote by the Marvel character Charles Xavier in a xmen comic from 1962 . He is the professor at the Xavier Institute for Higher Learning where they teach their students how to harness the powers they already possess, but can’t control. Now it’s a given that Professor Xavier is one of the most powerful mutants and his power specifically comes from his mind this quote is open to everyone in the world as we all have access to this same super power