10/22/2013 07:48 pm ET Updated Jan 23, 2014

Freud's Mistress

Did Sigmund Freud, the greatest figure in history to explain human sexuality and desire, have an affair with his wife's younger sister? Six years ago, a German sociologist finally resolved the burning question that has fascinated Freud scholars for the past century.

In the summer of 1898, Freud, then a robust 42, took a trip to Switzerland with his sister-in-law, Minna Bernays, who was then 33. The couple stayed at a popular hotel in the Swiss Alps and, remarkably, the hotel log from that time was still there. The sociologist found that not only had they stayed in a double room, but Freud had registered them as "Dr. Freud and frau."

In the past, most historians dismissed the persistent and nagging rumors relating to what they called "the Minna question." They argued that as revolutionary as Freud was in his research, he was deeply rooted in the morality of the Victorian age and highly conventional in his personal life. In fact, it would have been entirely out of character for him to have engaged in an illicit affair. But with the discovery of the hotel log, even previously skeptical biographers, such as Peter Gay, had to concede that it was likely that Freud and Minna were lovers.

The triangle of Freud, his wife, Martha and his wife's sister was provocative on many levels. How did this scandalous behavior begin and how and when did it end? How might it have affected Freud's theories regarding women, their desires, frustrations and repressed thoughts? And finally, how could one sister usurp the life and love of the other while they all lived under one roof?

We decided to write this story from the viewpoint of Minna, an independent, unmarried woman of high intellect, who was drawn to this seductive, narcissistic genius from the moment she moved into the household in 1895 and who eventually became, in Freud's own words, his "Muse and closest confidante,"

Upon further investigation, we discovered that Minna and Freud were probably still involved as late as 1907. This was when former Freud disciple, Carl Jung, visited the Freud home and claimed that Minna had confessed the affair to him in great detail and how it weighed upon her conscience. Previously, scholars had rejected Jung's account, calling it "sour grapes" since the two had an ugly falling out. To historians, this was simply Jung trying to discredit his mentor. But with the discovery of the hotel log, Jung's revelations have since been validated.

In addition, a cache of numbered letters released by the Freud museum to the Library of Congress turned out to have significant gaps. Those lost letters would have covered the years 1895-1900--the exact years that Minna and Freud were rumored to have had an affair.

We spent the next three years researching the private life of Sigmund Freud, his wife, and his sister-in-law. We were meticulous about the accuracy of the details, from the way the soup was served at exactly one, to Martha's arm paralysis, to Freud's cocaine and nicotine addictions, to the way his desk looked, to the children's personalities and, of course, the political and social milieu in which the family lived. What we found, was the untold story of the father of psychotherapy who was caught up in a scandalous love affair at the very time he was making his earth-shattering discoveries. He taught the world how to think---his favorite line was "the truth shall set you free." Yet, all the while, he was hiding a great secret of his own.

Excerpt: Freud's Mistress

It certainly wasn't the first time Minna saw Freud, but it felt that way. He walked in the room and gave her a curious smile. He was handsomer than she remembered, with a heftier build and finer clothes. In fact, he was impeccably groomed, wearing a pin-striped, three-piece wool suit and a black silk cravat. There was a simple gold chain, a chain that had belonged to her father that was attached to his watch, secured through a button hole, with the excess length draped across his vest. In one hand, he was holding a small antiquity, a solid bronze figurine and, in the other, a cigar. His hair was thick and dark, slightly graying at the temples. And then there were the eyes. Intense. Dark. Appraising.

Minna thought back to when she first met him, a new suitor for Martha. He was standing in the parlor of their home in Vienna, a poor Jew from the wrong side of town, whose family had neither social standing nor wealth. He was looking at Martha, and Minna was looking at him. It was twilight, the time when day and night slur together at a certain moment and then all the colors of the day fade to black. Her sister had been introduced to him a month before, but by the end of this particular visit the stage was set for both of them. Martha was almost giddy when she talked about him. But not their mother, a woman from a distinguished German-Jewish family who deemed the young doctor hardly worthy of her daughter. Nevertheless, two months later the couple was secretly engaged. Minna remembered thinking that Sigmund's wild infatuation and pursuit of Martha didn't seem quite real. As if they were playing at being in love, the courtship taking place in both of their minds. The swift progression of it all was baffling, at least to Minna.

During these first visits, her sister hardly talked. Martha was a soft, delicate little creature filled with hope. And Minna was a different version of herself as well. Back then, she was tall, and thin, all angles and tangled hair. Too much enthusiasm, too much talking, and far too clever. In those days, Sigmund got exactly what he wanted: an old-fashioned sweetheart, not a woman with opinions who engaged in serious conversations. Minna's role was clear from the beginning and she was ever mindful of that fact. Minna was the intellectual and Martha was the intended. And now here they were, Martha and Sigmund married, six children, married, married, married.

He stood there for a moment, watching Minna. She met his gaze and he gave her the same look he used to give her years ago, making her feel that it was more than simple recognition. Then he crossed the room and took his seat next to her empty chair, placing the antiquity on the table in front of him and snubbing out his cigar in a small, brass ashtray.

"My dear Minna," he said, " what do we owe this great pleasure?"

"To my getting dismissed," she said, smiling demurely. "Again."