Genius is the ability to independently arrive at and understand concepts that would normally have to be taught by another person.
Immanuel KantExperience without theory is blind, but theory without experience is mere intellectual play.
Immanuel KantBut although all our knowledge begins with experience, it does not follow that it arises from experience.
Immanuel KantThe sceptics, a kind of nomads, despising all settled culture of the land, broke up from time to time all civil society. Fortunately their number was small, and they could not prevent the old settlers from returning to cultivate the ground afresh, though without any fixed plan or agreement.
Immanuel Kant