[...] A feeling of intense well-being, of reconciliation with all mankind, is aroused in me whenever I reflect on your inestimable friendship. [...] That my wife had you for a doctor was fortunate for her, but that it should have been in Dresden was a misfortune. In any other place she would have been less exposed to all those influences [...] As to Paris, you are mistaken. My wife will live here with me in the greatest retirement. I have rented a very pleasant lodging on the outskirts of the town in a new, very quiet quarter, on high ground, in pure air, within reach of pleasant walks, the Bois de Boulogne, etc. I, too, need a quiet life to keep my health now; no social fuss and a maximum of peace and domestic comfort. I engage in my approaching enterprises here on the understanding that I stick strictly to the matter in hand and have absolutely nothing to do with the cultivation of coteries, which others think so necessary. Fortunately, my renown is so great even here in Paris, that I need have no considerations of this sort and can go my own way in peace. My wife will live very pleasantly and peacefully with me without either disturbing the other in the least. [...] I shall not entertain, nor shall I press my wife to accept any invitations which may be extended to me [...] On the other hand I count on many an evening call from a few old and very congenial German friends, and my wife can frequently amuse herself by going to theatres and concerts. All these, however, as everything else in Paris, will, as it were, stand in a certain detached relation to her, like that of the play to the audience, whereas in Dresden she was in a sense in the midst of the action. Believe me, dearest friend, in taking my wife from Dresden to Paris I know very well what I am doing and why. Moreover, having me always at her side, a thousand occasions of anxiety and troubled fancy will be removed from her. [...] It is another matter, however, with the project for our meeting in Karlsruhe at the time of the rehearsal and performance of my new work. [...] From the moment of my arrival there, I shall be involved in such multitudinous and exciting activities that, for the whole of my stay, I should be absolutely incapable of exerting a beneficial influence on my wife. I very much dread that period, particularly after having engaged in no activity of the kind for so long. The rehearsal for the first time of a new work like Tristan, requiring immense intellectual subtlety for its comprehension and extraordinary passion, is a task which I dare lay upon myself but seldom. Depression, almost despair, terrible excitement, superhuman nervous and even muscular exertions, will reduce me to a state in which I shall need any amount of consideration and tendance and be quite incapable of extending the same to others.—Add to that, our first sight of each other again, my wife's natural excitement, her worry about me and her anxiety for the success of my enterprise, my unbearable nervous irritability, etc. [...] The performance of Tannhäuser later in Paris will be quite a different matter. Owing to longer experience, my attitude to this older work is calm and objective.
I shall not myself conduct, but merely assist and see that all is properly understood. This will be an entertainment rather than an excitement for both of us. [...]
[...] I hope to bring off a performance of Tannhäuser in Paris this coming winter. If so, I may then be successful in selling the opera to a Parisian publisher and have the satisfaction of fulfilling my promise conscientiously and repaying at once no small part of my pecuniary debt to you. [...]
Source: Letters of Richard Wagner, Vol. 2, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 432