[...] I have just studied Nirvana again.—You most extraordinary person! How hard it will be for you to be somebody! And yet an inner voice tells me plainly how near you are to my heart and how I depend on you. If only you could understand your destiny! If you were to succumb under it, it would be because your heart and soul are set upon too radiant a model. In this revised work of your youth, I perceive unmistakably this overweeningness of the spirit. From no point of view could I pretend to disregard this piece. Such work done in youth marks you out for the very highest conceivable mastery of your art. Such originality, such diabolic clarity of expression are here, that it fills one with horror to be obliged to realise that it is a youthful work. There is too much in it, and that is a danger. And see, Hans, it is just the same with your heart. Fate has endowed it with a greatness, a beauty, only equalled by the grand scale on which your spirit as an artist has been planned. Do not sink down under the immensity of the tasks assigned you. Acknowledge them, recognise them in the eyes of your friend, look them courageously and proudly in the face, and if you shoulder them you become an example of rare nobility.—So that's settled, my dear Hans! All that is wanted now is care and wise cultivation. Your success can, and will, only come from within you. You have nothing to do but answer to your vocation, and this is an incomparably high and splendid one! [...]
Source: Letters of Richard Wagner, Vol. 2, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 628