[...] I find it extraordinarily difficult to answer your [...] letter, and I should probably have neglected to do so entirely if your son's action had not made it seem necessary for me to express my view of the situation.
You say you are agreed on the main issue that your son should follow his inclination and choose music definitely as his calling, and at the same time you tell me you wish me to advise Hans as to how in the immediate future he may usefully occupy himself with music in Berlin for a longer or shorter period.
Your son's talent is so far developed that I cannot now possibly advise him to do anything but give practical employment to his acquirements, learning through the exercise of his art whatever remains for him to learn. We musicians can only regard the actual practice of musical conducting as such a training. How your son is to get the offer of an opportunity to do this in Berlin, I cannot comprehend, for I am sure of this much at least, that it is everywhere uncommonly difficult for young practising inexperienced musicians to get entrance to just this practical side of their profession. It was a peculiar circumstance which chanced to give me the disposal of the conducting of music here in Zurich, and as soon as your son was in earnest about his musical calling he was, as a matter of course, as eager to grasp the opportunity offered through me of a practical education, as his parents would be to see him grasp it when offered, were they, on their side, really in earnest in wishing to create opportunity for their son. Only this was just the difficulty on his parents' part. Hans' mother has said candidly that she considers my personal influence over him dangerous. Not because I feel insulted by this, but because I perceive the impossibility of overcoming his mother's prejudice against me (unless, perhaps, she were to give me the honour of a nearer acquaintance!), I feel compelled personally to maintain silence towards Frau von Bülow. At the same time I can naturally only continue to have to do with one who trusts me, and then, indeed, only if he assures me of this spontaneously.
You [...] feel constrained to wish that the views of Hans' mother should prevail, and this [...] solely on the ground that you thereby avoid causing her any painful emotion. [...]
Such shortcomings as have struck you in the development of your son's character, closer investigation will show to have originated in the lack of direction in that development hitherto. [...] You thought good to restrain your son from visiting me at Zurich during his stay in Switzerland. I must take it that you did this for the same reasons which have swayed you throughout in this matter and not from animosity to me, for it is only upon this supposition that I can write to you at all. I need see no more than this in the fact that you made a point—I grant you only out of regard for Hans' mother—of preventing your son from meeting me in Zurich, just when the way stood open for his speedy and definite entry upon an artistic career. But it is just herein that I cannot but see with perfect clarity that Hans' parents' whole intention was still to dissuade their son from the actual choice of a musical calling. [...]
I confess that for this reason I strongly mistrust Hans' parents' sincerity as touching their consent to his choice of a profession, and it is this mistrust, since it less concerns myself than your son's life's happiness as an artist, which has given me strength to take upon myself to cross your decisions. [...] In Hans' last letter to me I got a painful impression of one under constraint in every respect. As he was particularly troubled by the belief that there was cause for anxiety as to the possibility of a livelihood in Zurich, supposing he were to come here without his parents' consent, I thought it only right for me to reassure him at least on that point by telling him of the post open to him here, so that he could base his decision definitely on the strength of his inclinations and on nothing else. [...] I am not in a position to judge whether or no it will please you to hear from me now that your son has really amazed me by the rank he has already attained as an artist, that I see in him a quite extraordinarily gifted and rapidly maturing artist, and that my hopes for him are so great that—pardon me!—any blame of yours which I may perchance incur at the moment, I can only accept as part of the bargain, and cancel it out against the greatness of my hope, for I know that your displeasure will pass away when success becomes apparent. Yes, I know that some day your gratitude to me will be as deep as your love for your son! [...]
Source: Letters of Richard Wagner, Vol. 1, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 190