Sigmund Freud skriver til sin venn Fliess og forsøker å forstå det seksuelle elementet som ligger under nevrosene

Sigmund Freud er i ferd med å sende sin kone Martha og barna til landet. Han føler seg bredre nå, men slett ikke helt bra. Han skriver til sin fortrolige venn Wilhelm Fliess i Berlin om sine tanker om seksualiteten og nevrosene (her gjengitt i engelsk oversettelse -- originalen er på tysk):

 Dearest friend, Dearest in truth, because I find it touching that you should so thoroughly go into my condition at a time when you are either very busy or not well or possibly both. There was a gap in your letter which had begun to look uncanny to me, and which almost induced me to write for information to a certain young lady in Berlin with whom I am acquainted and who, I hope, is on friendly terms with me as well. I promise you a detailed report on my illness next time; I feel better, but far from well; at least I am working again. Today I shall allow myself a good hour and chat only about science with you. It is obviously no special favor of fate that I have approximately five hours a year to exchange ideas with you, when I can barely do without the other -- and you are the only other, the alter.

Tomorrow I am sending the hen and the five little chicks to Reichenau, and during the sad loneliness that follows -- my sister-in-law Minna, otherwise my closest confidante, will depart two weeks later -- I shall more often carry out my resolution at least to write to you.

I put part of the neurosis story on paper for you when I was still in my worst period, but now I am stuck. I have a lot to do; in addition, the next installment of the Le¡ons du mardi,; the last case history for Breuer; continuing my neurosis collection; thus, I am making no progress.

Was not Marion Delorme a jewel? She will not be included in the collection with Breuer because the second level, that of the sexual factor, is not supposed to be disclosed there. The case history I am writing now -- a cure -- is among my most difficult pieces of work. You may have it before Breuer if you return it promptly. Among the gloomy thoughts of the past few months was one, in second place right after wife and children -- that I shall no longer be able to prove the sexual thesis. After all, one does not want to die either immediately or completely. I am pretty much alone here in the elucidation of the neuroses. They look upon me pretty much as a monomaniac, while I have the distinct feeling that I have touched upon one of the great secrets of nature. there is something odd about the incongruity between one's own and other people's estimation of one's intellectual work. ...

[summarizes favorable reactions to his oebook" on the diplegias, expectation of oenothing better than a respectable failure" of his Aphasia, OEObsessional Ideasà and forthcoming OEEtiology and Theory of the NeurosesÃ] ...

There are still a hundred gaps, large and small, in the matter of the neuroses, but I am getting closer to an outline and some general perspectives. I know three mechanisms: that of affect transformation (conversion hysteria), that of affect displacement (obsessional ideas), and that of exchange of affect (anxiety neurosis and melancholia). In every case it should be sexual excitation that undergoes these transpositions, but the impetus to them is not in every case something sexual; that is to say, in every case in which neuroses are acquired, it happens as a result of sexual disturbances, but there are people in whom heredity causes a disturbance of their sexual affects and who develop the corresponding forms of hereditary neurosis. The most general viewpoints under which I can classify the neuroses are the four following: (1) Degeneration (2) Senility (3) Conflict (4) Conflagration Conflagration is a new point of view; it means conditions of what might be called acute degeneration (for example, in severe intoxications, ... (Masson, 1985, pp. 73-74)"