"That life is difficult, I have often bitterly realized. I now had further cause for serious reflection. Right up to the present I have never lost the feeling of contradiction that lies behind all knowledge. My life has been miserable and difficult, and yet to others, and sometimes to myself, it has seemed rich and wonderful. Man's life seems to me like a long, weary night that would be intolerable if there were not occasionally flashes of light, the sudden brightness of which is so comforting and wonderful, that the moments of their appearance cancel out and justify the years of darkness."