[...] I thought it very friendly of you to let me know of the success of the Tristan performance at your theatre—only what could I say in reply? Did you put any question to me? The question which I, on the other hand, put to myself remained unspoken because I am myself still at a loss for the answer! You know that I did not want to permit this problematic work to be performed except when I could assist personally. Now it has succeeded without that—and I am astonished! Well, good luck! I certainly perceive hidden qualities in Seidl, which only need encouragement to amaze even me. And so, may I ask you for the sake of everything, to give him a freer hand even in scenic arrangements than is usually accorded to kapellmeisters, for this is the very point on which he has learnt most from me. [...]
As regards Paris, I should certainly prefer you to give up the project entirely, and really, I can hardly understand how I persuaded myself to do what you wanted for Paris. If you had not already spent money on the business, or if I knew how you could make good the money laid out for Paris in any other way, I would seriously endeavour to annul our contract, at the same time informing the Commission des auteurs dramatiques (of whom I am an associate) that I once for all refuse my consent to the theatrical production of any one of my works there in whatever language. You are, after all, too young and inexperienced as yet to understand clearly the implications of my attitude to this arrogant centre of culture—Paris. It simply revolts me to have anything to do with it! I fear that disagreeable experiences will some day make you feel as I do. [...]
Source: Letters of Richard Wagner, Vol. 2, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 731