Man is a Mystery

My soul is no longer susceptible to its former violent impulses. Everything in it is quiet as in the heart of a man who conceals a deep secret. I am learning a good deal about "what is man and what is life"; I can study human characters from writers with whom I spend the best part of my life, freely and joyfully. This is all I can say about myself. I have confidence in myself. Man is a mystery. It must be unraveled, and if it takes a whole lifetime, don't say that it's a waste of time. I am preoccupied by this mystery because I want to be a human being...

Fiodor Dostoievski, in 'Selected Letters'