Sigmund Freud skriver til sin venn Wilhelm Fliess i Berlin (her gjengitt i engelsk oversettelse -- originalen er på tysk):
"Hysterical cold shivers = being taken out of a warm bed. Hysterical headache with sensations of pressure on the top of the head, temples, and so forth, is characteristic of the scenes where the head is held still for the purpose of actions in the mouth. (Later reluctance at photographer's, who holds the head in a clamp.)
Unfortunately, my own father was one of these perverts and is responsible for the hysteria of my brother (all of whose symptoms are identifications) and those of several younger sisters. The frequency of this circumstance often makes me wonder. In any case, I shall bring a lot of strange material with me to Prague."
Freud, S., et al. (1985). The complete letters of Sigmund Freud to Wilhelm Fliess : 1887-1904. Cambridge, Mass, Belknap Press of Harvard University Press. s. 230-31
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