[...] Perhaps you will permit me to write once more briefly about your son, Herr Joseph, and to explain what would, in my opinion, be the best attitude for you to adopt towards the young man.
Well as I can understand your fatherly anxiety about the career which your son has entered upon (a career easily open to misconception), in my opinion it only needs a little strength of mind to throw off that anxiety once for all, and with it all your fears for your son.
Joseph's efforts to comply with your desire that he should employ his talent in attaining a materially good position in life were certainly honest, but just as certainly were they rendered void by his temperament. One reason for this is doubtless to be found in certain morbid tendencies which might, I am convinced, lead to the most regrettable excesses if he were forced to continue those efforts. A perception of the nature and of the value of true art has in him grown to be a matter of actual religious faith, rooted in the most passionate sensibilities of his soul. If you would allow him, freely and securely, the modest means for an exceptionally sober and frugal way of life, you would keep him happy in the service of a noble ideal to which few, unfortunately, are able to devote themselves freely and unconstrainedly. And here I venture to ask again, what nobler use could be made of ample even if hard-earned wealth than to provide a man, a son, with true freedom at a time when his exceptional gifts need to be developed and fostered? If, for instance, the King of Bavaria had not given me similar freedom in season, I had long since departed from this world in silence, for my art would have become abhorrent to me if I had had to turn it into money. I am bringing up my own son, so that should he decide to devote himself to any form of art, he may be able to serve the world as an independent man on the modest means which I hope to leave him.
Should certain temperamental dispositions prevent your son from himself attaining the highest ends, he may yet, as a free man, do them most valuable service. Not all men are capable of everything! But one thing is certain—that to drive and compel him to accept an alien vocation must make him thoroughly unhappy.
Forgive [...] these outpourings which I have felt urged to inflict on you solely by my perception of the silent conflict proceeding in your son, who has become dear to me. [...]
Source: Letters of Richard Wagner, Vol. 2, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 729