In short, enlightenment is achieved through the liberation of the imagination. It occurs when one abandons their pre-conceived notions of established truth and distances oneself from foreign influence to attempt to produce entirely original, progressive ideas. In order to do this Kant claims you must, “…have courage to use your own reason”, and be unafraid of failure. Enlightenment is an individualistic movement—It cannot be obtained by relying on others, and according to Kant, one must free themselves of previous impressions and political barriers. Our imaginations are shaped through derived images, thoughts, and memories that we have absorbed and perceived throughout our lives, and enlightenment is a product of transcendence of these aspects that are now deemed as limitations. Pure enlightenment is a difficult concept to grasp and imagine, and Kant believes only a minority will achieve it.
One could argue that Frederick II had an enlightened view on his role as king. Frederick II takes the stance that the king is the servant to the state, and not vice-versa. Many kings throughout history have succumbed to the indulgences that compliment the responsibility, and for his time period, Frederick II had a progressive attitude towards his position in society.