Wilhelm Fliess was born on 24th October 1858. He established himself as an ear, nose, and throat specialist in Berlin. Fliess was an associate of Josef Breuer and when he visited Vienna in November, 1887, he was advised by his friend to attend a lecture given by Sigmund Freud. After the lecture Breuer introduced Fliess to Freud. (1)
That night Freud wrote a letter to Fliess: "While my letter of today has a business motive. I must introduce it with the confession that I entertain the hope of continuing the relationship with you, and that you have left a deep impression on me." It was the beginning of a very close friendship. (2)
Freud had very few patients during the first few years of his married life. His first patient was suffering from depression and Freud prescribed electrical treatment. He also gave lectures to young doctors on a wide variety of topics, including clinical neurology and medical uses of electricity. Freud took a close interest in the work of Jean Martin Charcot and his "latest investigations upon hysteria... He had proved, for instance, the genuineness of hysterical phenomena and their conformity to laws... the frequent occurrence of hysteria in men, the production of hysterical paralyses and constructures by hypnotic suggestion." (3)
Freud discussed these issues with Josef Breuer. Both men began to use hypnotic suggestion to treat patients suffering from hysteria. This was a term used at the time that meant "ungovernable emotional excess" in women. This included anxiety, nervous coughs, shortness of breath, migraines, contorted facial muscles, paralyzed limbs, tics, muteness, fainting, insomnia, irritability and promiscuity. Charcot believed hysteria to be a disturbance of the nervous system and claimed both men and women could suffer from hysteria. (4)
Hypnosis is a state of human consciousness involving focused attention and reduced peripheral awareness and an enhanced capacity to respond to suggestion. Charcot's idea was you could use hypnosis not only to replicate the hysterical attack but to introduce suggestions to the hysteric that might enable a cure. Freud initially hypnotized patients by pressing his hand on their foreheads. However, Freud found, however, that he was not always able to induce hypnosis, either at all or deeply enough for his needs. (5)
In the autumn of 1892 Ilona Weiss became one of Freud's patients. To protect her identity, Freud always referred to her as "Elisabeth von R". The twenty-four year old daughter of a wealthy Hungarian family was suffering from pains in the legs and had difficulty in walking. Her doctor had examined her and could not find anything physically wrong with her legs and decided she was suffering from hysteria and she was sent to Freud. He decided to use a different method to treat her. Freud asked Elisabeth to lie down on his couch and close her eyes. Applying pressure to her forehead, he asked her to report faithfully whatever came into her mind. (6)
Elisabeth admitted that she was in love with her brother-in-law. However, she was able to suppress these feelings but did seek out his company and enjoyed long walks together. Her troubles began when her sister died and she developed the idea that he could become her husband. This "unacceptable thought" challenged everything that she believes about herself as a moral and loyal person. She resisted it and tried to force it out of her consciousness. It was because of these feelings that caused the pain in her legs. Freud believed the symptom can be traced back to the very walks that she had enjoyed with her brother-in-law before the death of her sister. Freud argues that far from being the degenerate fiends of popular myth, invariably the hysteric is too moral, punishing herself for her unacceptable desires. Elisabeth's treatment involved recovering her guilty thoughts from her unconscious and accepting it. This resulted in a full cure and in the spring of 1894 he attended "a private ball" where he saw "my former patient whirl past me in a lively dance". (7)
Sigmund Freud continued to experiment with encouraging patients to talk freely, without censorship or inhibition, about whatever ideas or memories occurred to them. Freud then used these comments to help discover the link with other events and feelings. During this process it was for the doctor to "decide what is and is not relevant: the patient must shape the discourse". This approach, "if it is to be effective, has to be understood as a partnership". (8)
In 1895 Sigmund Freud and Josef Breuer published their book, Studies on Hysteria. It consists first of a reprint of the joint paper they had written, then five case histories, a theoretical essay by Breuer, and a concluding chapter on psychotherapy by Freud. The first case history, by Breuer, is that of Anna (Bertha Pappenheim). Freud contributed the other four cases, including Ilona Weiss (Elisabeth) and Fanny Moser (Emmy).
The book received mainly hostile reviews. The best one appeared in the Neue Freie Presse, the leading daily newspaper of Vienna, by Alfred von Bergner, Professor of the History of Literature in the University of Vienna. He said he read the case histories with admiration and understanding, and then added the significant prediction: "We dimly conceive the idea that it may one day became possible to approach the innermost secret of human personality... The theory itself is in fact nothing but the kind of psychology used by poets." (9)
Havelock Ellis, a doctor working in London, and a founder member of the Fabian Society, also praised the book, and agreed with Freud's views about the sexual cause of hysteria. However, most people were shocked by the idea and it took over thirteen years to sell 626 copies of the book. It was not a very profitable exercise and the authors only received 425 gulden between them (£18 each). During the writing of the book the two men disagreed about the role that sexual impulses played in hysteria. (10)
David Stafford-Clark has pointed out: "Despite the comparative success of their joint publication, Breuer and Freud never collaborated in any further published material.... This in fact heralded not only the break with Breuer but the beginning of the independent emergence of Freud's own concept of psychoanalysis. The basic difference of opinion between the two authors, upon which Freud was later to lay considerable emphasis, concerning the part played by sexual impulses in the causation of hysteria." (11)
After the loss of Josef Breuer, Sigmund Freud formed a close relationship with Wilhelm Fliess, an ear, nose, and throat specialist. Breuer considered Fliess to be "one of the richest intellects" he had ever met. Fliess was very interested in new ideas and was very knowledgeable in the fields of the arts, mathematics and biology. Fliess acted as a sounding board for Freud's developing ideas. (12)
Ernest Jones, one of Freud's closest friends, spoke highly of Fliess. "His (Fliess) scientific interests ranged far beyond his own special field, particularly in medicine and biology. It was this extension that interested Freud and at first seemed to fit in with his own." (12a)
Their friendship grew through their frequent letters and regular meetings in Vienna and Berlin, but most of all liked to arrange two or three-day trips away from home (they called these special meetings "Congresses"). They not only exchanged their unorthodox scientific ideas but Freud provided intimate details of his own life (which he withheld from wife). In fact, it has been claimed that Freud used these letters as "self-analysis". (13) Freud became infatuated with Fliess: "Only someone who knows he is in possession of the truth writes as you do." (14)
During this period Freud's moods swung wildly from elation to depression: "Sometimes he convinced himself of the value of his discoveries; at other times he was plagued with self-doubt. In addition he was troubled with anxiety symptoms: fear of travelling by rail, dread of dying, shortness of breath and cardiac arhythmias, headaches and recurrent sinusitis... Yet out of this turmoil... some of Freud's most profound insights arose." (15)
Sigmund Freud reported in October, 1895: "I am almost certain that I have solved the riddles of hysteria and obsessional neurosis with the formulas of infantile sexual shock and sexual pleasure, and I am equally certain that both neuroses are, in general, curable - not just individual symptoms but the neurotic disposition itself. This gives me a kind of faint joy - for having lived some forty years not quite in vain - and yet no genuine satisfaction because the psychological gap in the new knowledge claims my entire interest." (16)
It was only after the death of his father in 1896, that Freud could begin to open up about how his own early sexual life had influenced his personality. "The chief patient I am preoccupied with is myself. My little hysteria, though greatly accentuated by my work, has resolved itself a bit further. The rest is still at a standstill. That is what my mood primarily depends on. The analysis is more difficult than any other. It is, in fact, what paralyzes my psychic strength for describing and communicating what I have won so far. Still, I believe it must be done and is a necessary intermediate stage in my work." (17)
Freud became convinced that most cases of neurosis can be traced back to incidents in early childhood but did not have full access to those memories that had been repressed into the unconscious. "I have not succeeded in gaining a theoretical understanding of repression and its interplay of forces. It seems once again arguable that only later experiences give the impetus to fantasies, which then hark back to childhood, and with this the factor of a hereditary disposition regains a sphere of influence from which I had made it my task to dislodge it - in the interest of illuminating neurosis." (18)
In a letter written on 15th October, 1897, Freud begins to explore what later became known as the Oedipus complex. "My self-analysis is in fact the most essential thing I have at present and promises to become of the greatest value to me if it reaches its end... Being totally honest with oneself is a good exercise. A single idea of general value dawned on me. I have found, in my own case, too, the phenomenon of being in love with my mother and jealous of my father, and now I consider it an universal event in early childhood... If this is so, we can understand the gripping power of Opedius Rex... the Greek legend seizes upon a compulsion which everyone recognizes because he senses its existence within himself. Everyone in the audience was once a budding Oedipus in fantasy and each recoils in horror from the dream fulfillment here transplanted into reality, with the full quantity of repression which separates his infantile state from his present one." (19)
Freud is referring to Oedipus Rex, an Ancient Greek drama written by Sophocles in about 429 BC. Oedipus is the son of Laius and Jocasta, the king and queen of Thebes. When his son is born, the king consults an Oracle as to his fortune. To his horror, the oracle reveals that Laius "is doomed to perish by the hand of his own son". Laius orders Jocasta to kill him. Unable to kill her own son, she gives him to a servant to carry out the task. He abandons Oedipus on a mountain top but he is rescued by a local shepherd. He presents him to the childless king Polybus, who raises Oedipus as his own son.
As he grows to manhood, Oedipus hears a rumour that he is not truly the son of Polybus. He asks an oracle who his parents really are. The Oracle seems to ignore this question, telling him instead that he is destined to "mate with his own mother, and kill his own father ". Desperate to avoid this terrible fate, Oedipus, decides to leave Corinth. On the road to Thebes, Oedipus encounters Laius and the two men quarrel over whose chariot has the right of way. The king attempts to strike Oedipus with his sceptre, but during the struggle Laius is killed.
Before arriving at Thebes, Oedipus encounters the Sphinx, a legendary beast with the head and breast of a woman, the body of a lioness, and the wings of an eagle. The Sphinx was sent to the road approaching Thebes as a punishment from the gods, and would kill any traveler who failed to answer a certain riddle:"what is the creature that walks on four legs in the morning, two legs at noon, and three in the evening?" Oedipus correctly guesses, "man", who crawls on all fours as an infant, walks upright in maturity, and leans on a stick in old age. The Sphinx throws herself from a cliff, thereby ending the curse. Oedipus' reward for freeing Thebes from the Sphinx is its kingship, and the hand of the now widowed queen, Jocasta. The couple have two daughters, Antigone and Ismene.
Many years later another oracle discloses the truth of how Oedipus has killed his own father and married his mother. Oedipus decides to cut out his mother's womb. However, before he can do this, she hangs herself. Oedipus takes her down and removes the long gold pins that held her dress together, before plunging them into his own eyes in despair. A blind Oedipus now leaves the palace and the chorus repeat the Greek maxim, that no man should be considered fortunate until he is dead.
Sigmund Freud argues that rather than see Oedipus' fate as a horrifying and individual event, he sees it as expressing "the long-forgotten desires of childhood that accompany and shape every individual's sexual development" and "between the ages of three and five, every child must struggle with what comes to be called the Oedipus complex, when, like the Greek king, they long to be rid of the parent of the same sex in order to take possession of the parent of the opposite sex". (20)
Freud later destroyed all of Wilhelm Fliess' letters, but it becomes clear that he advocated the theory that all adults were bisexual and that these repressed desires were the cause of some cases of hysteria. On 25th March, 1898, Freud wrote to Fliess: "I do not in the least underestimate bisexuality.... I expect it to provide all further enlightenment." (21) A year later he said: "Bisexuality! You are certainly right about it. I am accustoming myself to regarding every sexual act as a process which four individuals are involved." (22)
Freud told Fliess that he always needed a very close male friend and that he was disappointed by the end of his relationship with Josef Breuer: "In my life, as you know, woman has never replaced the comrade, the friend. If Breuer's male inclination were not so odd, so timid, so contradictory - like everything else in his mental and emotional makeup - it would provide a nice example of the accomplishments into which the androphilic current in men can be sublimated." (23)
Freud admitted to Fliess that the theories emerging from his self-analysis was not really science. His attempts at analyzing his personality was more the work of an artist: "I am actually not at all a man of science, not an observer, not an experimenter, not a thinker. I am by temperament nothing but a conquistador - an adventurer, if you want it translated - with all the curiosity, daring, and tenacity characteristic of a man of this sort." (24)
In January 1899, Sigmund Freud wrote to Fliess declaring he had made a break-through in understanding the human personality: "I want to reveal to you that the dream schema is capable of the most general application, that the key to hysteria as well really lies in dreams... If I wait a little longer, I shall be able to present the psychic process in dreams in such a way that it also includes the process in the formation of hysterical symptoms. So let us wait." (25)
The following month he wrote: "My last generalization has held good and seems inclined to grow to an unpredictable extent. Not only dreams are wish fulfillments, so are hysterical attacks. This is true of hysterical symptoms, but probably applies to every product of neurosis, for I recognized it long ago in acute delusional insanity. Reality - wish fulfillment - it is from these opposites that our mental life springs. I believe I now know what determines the distinction between symptoms that make their way into waking life and dreams. It is enough for the dream to be the wish fulfillment of the repressed thought, for dreams are kept at a distance from reality. But the symptom, set in the midst of life, must be something else besides: it must also be the wish fulfillment of the repressing thought." (26)
During this period Freud gradually abandoned the use of hypnotism, finding it difficult to induce and being uncertain in its effects. He now asked his patient to relax on a couch and they were asked to try and recall anything that seemed relevant to a particular symptom. At first he would press the patient's forehead with his hand and insist that some thoughts would occur. However, by 1899 he adopted a "less interventionist approach, realizing that he would learn more by allowing the patient's thoughts to evolve freely." (27)
The first edition of The Interpretation of Dreams was published in November 1899 but it did not become available to the following year. The publisher printed 600 copies. In the six weeks following publication 123 copies were sold, but only a further 228 were purchased over the next two years. According to David Stafford-Clark: "This book is now universally regarded as Freud's theory of dreams, and a confirmation of his earlier theories of unconscious mental mechanism, brilliantly exemplified. Freud himself never doubted the importance of the book and of his discoveries therein recorded, which had changed his own life." (28)
Sigmund Freud told his friend, Ernest Jones, it was his favourite book: "It seems to be my fate to discover only the obvious: that children have sexual feelings, which every nursemaid knows; and that night dreams are just as much a wish fulfillment as day dreams." However, it did not make him very much money as he only received 522.40 gulden (£41 16s.) from the publisher. (29)
The scientific journals did not bother to review The Interpretation of Dreams. A couple of newspapers did report on the book and one academic, Professor Raimann, claimed that Freud had constructed a theory "so that he can fill his pockets adequately". Another academic made a more valid point when he argued that the "imaginative thoughts of an artist had triumphed over the scientific investigator." (30)
In a letter written in August 1901, Freud admitted that Wilhelm Fliess had played an important role in the development of its ideas. "You remember my telling you years ago, when you were still a nose specialist and surgeon, that the solution lay in sexuality. Several years later you corrected me, saying that it lay in bisexuality - and I see that you are right. So perhaps I must borrow even more from you; perhaps my sense of honesty will force me to ask you to co-author the work with me; thereby the anatomical-biological part would gain in scope, the part which, if I did it alone, would be meager. I would concentrate on the psychic aspect of bisexuality and the explanation of the neurotic. That, then, is the next project for the immediate future, which I hope will quite properly unite us again in scientific matters as well." (31)
However, Freud appeared to drop the idea and Fliess became worried that he was steal his ideas and use them in his own book on the subject. After Fliess complained about this Freud stopped writing to him. He also destroyed all the letters Fliess had sent him. Fliess claimed that at their last meeting, Freud was extremely hostile and expressed the desire to kill him. (32)
In a footnote that appeared in a later book, Freud pointed out that in the summer of 1901 he did have a "lively exchange of scientific ideas" with an unnamed friend. He explained how later his friend accused him of stealing his ideas. Freud rejected this view but added that "since then I have grown a little more tolerant when, in reading medical literature, I came across one of the few ideas with which my name can be associated, and find that my name has not been mentioned." (33)
In 1903 Otto Weininger published a book entitled, Sex and Character. Wilhelm Fliess read the book the following year and was shocked that it contained ideas about bi-sexuality. Fliess discovered that Weininger was a close friend of Hermann Swoboda, a close associate of Freud and came to the conclusion that his ideas on sexuality had been passed on to the young writer. In a letter written in July 1904, Fliess wrote that he had found in Weininger's book "my ideas on bisexuality and the nature of sexual attraction that follows from it - feminine men attract masculine women and vice versa." (34)
Freud replied that Swoboda was not a pupil, but a patient to whom he had mentioned in the analysis that a bisexual constitution was universal and who had then casually made the same remark to Weininger. He then pointed out that Weininger had committed suicide after he had been accused of plagiarism by Paul Julius Möbius. "The late Weininger was a burglar with a key he had found". (35)
Wilhelm Fliess replied that he had evidence that Freud had met with Weininger while he was writing the book. Freud now admitted that he had done this and "confessed he must have been influenced by his wish to rob Fliess of his originality, a wish presumably compounded of envy and hostility." (35)
In 1906 Wilhelm Fliess published The Course of Life: Foundation of Exact Biology, which spelled out his theories of bisexuality in exhaustive detail. This was followed by a pamphlet denouncing Swoboda and Weininger as plagiarists and accusing "Freud of being the conduit through which they had secured access to Fliess's original property. What offended Freud most about this polemic was that it quoted from his private communications to Fliess." (36)
Wilhelm Fliess died on 13th October 1928. Two months later his wife wrote to Freud asking for her husband's letters. Freud replied: "My memory tells me that I destroyed the larger part of our correspondence some time after 1904." He then added: "I would certainly like to hear that my letters to your husband, my intimate friend for long years, have found a fate that would protect them from any future utilization." (37)
On 30th December, 1936, Freud received information from Marie Bonaparte that a bookseller from Berlin owned the letters that he had sent to Wilhelm Fliess. (38) Freud was appalled as when Fliess had died in October 1928, he had asked his widow to return the letters. However, she told him that she could not find them. He told Bonaparte that the letters were "the most intimate you can imagine" and that it is important that they were destroyed. "It would be most awkward" to have the letters "fall into the hands of strangers" and "I want none of them to come to the notice of so-called posterity". (39)
Freud attempted to buy the letters but the bookseller refused as he feared that he would destroy them. Marie Bonaparte agreed to buy them but refused to destroy the letters. She promised not to read them, but proposed to deposit the letters in some safe library with the stipulation that they be kept from anyone's eyes "for eighty or a hundred years after your death." She added: "You belong to history of human thought like Plato, let us say, or Goethe... Something would be lost to the history of psychoanalysis, this unique new science, your creation, which is more important than even Plato's ideas." (40)
Freud had always been highly secretive and had been destroying documents for most of his professional life. In one letter to Martha Freud he wrote: "I have destroyed all my notes and letters accumulated for 14 years, all scientific abstracts and manuscripts of my work; only some family letters have been spared. All my old friendships and relations presented themselves again and silently took the deadly blow... I cannot mature and cannot die, worrying about who will lay their hands on my old papers. The biographers should work it out somehow, we don't want to make it too easy for them." (41)
Ernest Jones made very little use of the Freud-Fliess correspondence in his book, The Life and Work of Sigmund Freud (1953). It was not until the following year that with the permission of Marie Bonaparte and Anna Freud the letters were published as The Origins of Psycho-Analysis: Letters to Wilhelm Fliess, Drafts and Notes, 1887-1902 (1954).
Your kind-heartedness is one of the reasons I love you. initially, it seemed to me that you had broken off contact because of my remarks about the mechanism of the symptoms distant from the nose, and I did not deem this improbable. Now you surprise me with a discussion that takes those ideas seriously!
You are right that I am overflowing with new ideas, theoretical ones as well. My theories on defense have made an important advance of which I shall give you an account next time. Even the psychological construction behaves as if it would come together, which gives me immense pleasure. Reporting on it now would be like sending a six-month fetus of a girl to a ball...
I need a lot of cocaine. Also, I have started smoking again, moderately, in the last two to three weeks, since the nasal conviction has become evident to me. I have not observed any ensuing disadvantage. If you again prohibit it, I must give it up again. But do consider whether you can do this if it is only intolerance and not etiology. I began it again because I constantly missed it (after fourteen months of abstinence) and because I must treat this psychic fellow well or he won't work for me. I demand a great deal of him. The torment, most of the time, is superhuman.
I am working on psychology, vigorously and in solitude; I cannot yet send you anything that is halfway finished, no matter how much I reduce my standards concerning what is finished. I believe more and more firmly in the chemical neurone theory; I started with assumptions similar to those you described, but now I am stuck after I ruined my head with it yesterday.
I feel more certain about consciousness and must now make an attempt to deal with this most difficult of all things in my lectures on hysteria. On Saturday I lectured on dream interpretation to the youths of the Jewish academic reading circle; someday you will hear about what it contained; right now I am in no mood for presentations.
I am as isolated as you would wish me to be. Word was given out to abandon me, for a void is forming all around me. So far I bear it with equanimity. I find it more troublesome that this year for the first time my consulting room is empty, that for weeks on end I see no new faces, cannot begin any new treatments, and that none of the old ones are completed. Things are so difficult and trying that it requires, on the whole, a strong constitution to deal with them.
By one of those dark pathways behind the official consciousness the old man's death (Jacob Freud) has affected me deeply. I valued him highly, understood him very well, and with his peculiar mixture of deep wisdom and fantastic lightheartedness he had a significant effect on my life. By the time he died, his life had long been over, but in my inner self the whole past has been awakened by this event. I now feel quite uprooted.
I must tell you about a nice dream I had the night after the funeral. I was in a place where I read a sign. You are requested to close the eyes.
I immediately recognized the location as the barbershop I visit every day. On the day of the funeral I was kept waiting and therefore arrived a little late at the house of mourning. At that time my family was displeased with me because I had arranged for the funeral to be quiet and simple, which they later agreed was quite justified. They were also somewhat offended by my lateness. The sentence on the sign has a double meaning: one should do one's duty to the dead (an apology as though I had not done it and were in need of leniency), and the actual duty itself. The dream thus stems from the inclination to self-reproach that regularly sets in among the survivors.
My last generalization has held good and seems inclined to grow to an unpredictable extent. Not only dreams are wish fulfillments, so are hysterical attacks. This is true of hysterical symptoms, but probably applies to every product of neurosis, for I recognized it long ago in acute delusional insanity. Reality-wish fulfillment - it is from these opposites that our mental life springs. I believe I now know what determines the distinction between symptoms that make their way into waking life and dreams. It is enough for the dream to be the wish fulfillment of the repressed thought, for dreams are kept at a distance from reality. But the symptom, set in the midst of life, must be something else besides: it must also be the wish fulfillment of the repressing thought. A symptom arises where the repressed and the repressing thought can come together in the fulfillment of a wish. The symptom is the wish fulfillment of the repressing thought, for example, in the form of a punishment; self-punishment is the final substitute for self-gratification, which comes from masturbation.
This key opens many doors. Do you know, for instance, why X.Y. suffers from hysterical vomiting? Because in fantasy she is pregnant, because she is so insatiable that she cannot bear being deprived of having a baby by her last fantasy lover as well. But she also allows herselt to vomit, because then she will be starved and emaciated, will lose her beauty and no longer be attractive to anyone. Thus the meaning of the symptom is a contradictory pair of wish fulfillments.
(1) Peter Gay, Freud: A Life for Our Time (1989) page 55
(2) Sigmund Freud, letter to Wilhelm Fliess (24th November, 1887)
(3) Sigmund Freud, Autobiography (1923) page 2
(4) Elisabeth Young-Bruehl, Freud on Women (2002) page 1
(5) Ernest Jones, The Life and Work of Sigmund Freud (1961) page 210
(6) Beverley Clack, Freud on the Couch: A Critical Introduction to the Father of Psychoanalysis (2013) page 38
(7) Sigmund Freud and Josef Breuer, Studies on Hysteria (1895) pages 160-161
(8) Beverley Clack, Freud on the Couch: A Critical Introduction to the Father of Psychoanalysis (2013) pages 39-40
(9) Alfred von Bergner, Neue Freie Presse (2nd December 1895)
(10) Ernest Jones, The Life and Work of Sigmund Freud (1961) page 224
(11) David Stafford-Clark, What Freud Really Said (1965) page 39
(12) Laurence Spurling (editor), Sigmund Freud: Critical Assessments (1989) page 305
(12a) Ernest Jones, The Life and Work of Sigmund Freud (1961) page 251
(13) Stephen Wilson, Sigmund Freud (1997) page 49
(14) Elisabeth Young-Bruehl, Freud on Women (2002) page 50
(15) Sigmund Freud, letter to Wilhelm Fliess (12th December, 1897)
(16) Sigmund Freud, letter to Wilhelm Fliess (16th October, 1895)
(17) Sigmund Freud, letter to Wilhelm Fliess (14th August, 1897)
(18) Sigmund Freud, letter to Wilhelm Fliess (21st September, 1897)
(19) Sigmund Freud, letter to Wilhelm Fliess (15th October, 1897)
(20) Beverley Clack, Freud on the Couch: A Critical Introduction to the Father of Psychoanalysis (2013) page 63
(21) Sigmund Freud, letter to Wilhelm Fliess (25th March 1898)
(22) Sigmund Freud, letter to Wilhelm Fliess (1st August, 1899)
(23) Sigmund Freud, letter to Wilhelm Fliess (1st August, 1899)
(24) Sigmund Freud, letter to Wilhelm Fliess (1st February, 1900)
(25) Sigmund Freud, letter to Wilhelm Fliess (3rd January, 1899)
(26) Sigmund Freud, letter to Wilhelm Fliess (19th February, 1899)
(27) Stephen Wilson, Sigmund Freud (1997) page 50
(28) David Stafford-Clark, What Freud Really Said (1965) page 67
(29) Ernest Jones, The Life and Work of Sigmund Freud (1961) page 299
(30) Ernest Jones, The Life and Work of Sigmund Freud (1961) page 307
(31) Sigmund Freud, letter to Wilhelm Fliess (7th August, 1901)
(32) Laurence Spurling (editor), Sigmund Freud: Critical Assessments (1989) page 311
(33) Sigmund Freud, The Psychopathology of Everyday Life (1904) page 143-144
(34) Wilhelm Fliess, letter to Sigmund Freud (20th July, 1904)
(34) Sigmund Freud, letter to Wilhelm Fliess (27th July, 1904)
(35) Ernest Jones, The Life and Work of Sigmund Freud (1961) pages 272-273
(36) Peter Gay, Freud: A Life for Our Time (1989) page 155
(37) Sigmund Freud, letter to Ida Fliess (17th December, 1928)
(38) Marie Bonaparte, letter to Sigmund Freud (30th December, 1936)
(39) Sigmund Freud, letter to Marie Bonaparte (3rd January, 1937)
(40) Marie Bonaparte, letter to Sigmund Freud (7th January, 1937)
(41) Sigmund Freud, letter to Martha Freud (28th April, 1885)