The patient thereupon produced some of her childish sex theories, and a memory of the odour of her mother’s body, which she had noticed when she had been allowed to get into her mother’s bed. The author’s patient’s childish theory on the matter is also interesting. It attributed the inexplicable sensation of familiarity with a new experience to a previous life, in which her soul had resided in the body of another animal. Moreover the doctrine of the transmigration of souls, can be regarded as a projection into mythology of the intuition which ever and again forces itself upon psychoanalysts that the human mind contains unconscious memory traces of phylogenetic development. If psychoanalysts take into consideration Sigmund Freud’s original explanation, i.e. that the sensation of deja vu generally signifies the memory of an unconscious daydream, their can draw the conclusion that deja vu should be included among the ‘passagere symptom formations’ and always means a confirmation from the unconscious.