The cases of the writers Marcel Proust and Franz Kafka are examples of the relationship among genius, memory and sleep.
The interest of Marcel Proust on involuntary memory may be related to his medical history. The novelist suffered from bronchial asthma and insomnia. At that time, asthma was considered a nervous habitus, and a diagnosis of neurasthenia was performed. Proust was admitted to Paul Sollier’s Clinic in Paris, to try to treating his neurasthenia and insomnia. Sollier studied several aspects of the memory, and used the surges of involuntary memory to treat
his patients. So, Proust experienced the surges of involuntary memory, which himself cited in the famous episode of «les Madeleines» in his masterpiece «In search of lost time».

If the memory is a central element in Proust’s work, the sleep plays a pivotal role in Kafka. Insomnia affected Kafka’s life and literary work. He considered the sleep as the most innocent creature, and the insomnia as a rejection of the natural. At the same time, he was afraid of sleep, because it represented an area where the consciousness was lost. Insomnia allowed him to write and to refuge into literature. So, Franz Kafka, used the insomnia for their creative processes. He wrote in a sleep-deprived state, because it provided access to otherwise inaccessible thoughts. In his diaries he wrote: « it was the power of my dreams, shining forth into wakefulness even before I fall asleep, which did not let me sleep.» It seems to be a description of an hypnagogic hallucination. Many references to the importance of the sleep may be found in the brief story «Metamorphosis».