[...] In the mean time I have seen the Prophet for the first time in this life, in fact I saw it the evening before I received your last letter, enclosing the book, for which I was most grateful. During the last act I was unfortunately distracted by a banker, who was talking in his box in an uncommonly loud voice. Otherwise I was able to convince myself - at the opera’s 47th performance - that the work has been accorded a great and lasting - and undeniable - success by the Paris Opera audience: the house is always full to overflowing, and the applause more enthusiastic than anything I’ve otherwise found here. -
I am happy to be able to inform you that I have now discovered the basic cause of my illness: to a large extent it was an emotional disorder, or rather it was an involuntary affliction of my mind whose physical symptoms increased to such an alarming degree that they finally made themselves felt. I have recently given full expression to the motives which prompted my decision not to write an opera for Paris, and I did so in a fairly detailed letter to Frau Laussot, the contents of which will have been passed on to you by this truly excellent friend; what I said here was that in no circumstances would I write an opera for Paris but that, at most, I would agree to hand over an already completed work, Lohengrin, which has since lost its appeal for me, and which may be plucked and woven into the garland that graces the brow of Paris’s grand opera whore: but since I am not so naive as to believe that this gift will be seen as a decent offering, and since, moreover, it is impossible for me even so much as to lift my pen in furtherance of this business of selling myself, I assume that I shall have to deny my dear friends Heine and Fischer (to whom I do not yet dare to communicate this decision) the pleasure of seeing a Wagnerian swan-knight swimming across the Rhine. - What was useful about all this for me was that I began to feel better the moment I sent off the letter, an improvement in my condition which continued yesterday when I received my friend’s reply containing her sincere congratulations on my decision. So as not to have wasted my time altogether, I intend waiting for the performance of my Tannhäuser Overture before travelling south, taking in Bordeaux, in an attempt to regain perfect health. That, my dear friend, is how the horse cures itself in the wilderness, by biting open one of its veins; in my case the vein is the Paris opera: I delight in feeling this unhealthy blood oozing from the veins in which it had begun to thicken.
[...]
Source: Selected Letters of Richard Wagner, trans. and ed. Stewart Spencer and Barry Millington (W. W. Norton & Company, 1988), No. 101