Medard Boss: But according to psychoanalytic theory, the act of leaving something behind, for instance, a purse, in leaving an acquaintance's room, expresses the unconscious wish to return there. How is such a "leaving behind" to be described phenomenologically?
Martin Heidegger: There is no unconscious intention when the purse is left behind. On the contrary, in this case leaving [the room] is entirely different from leaving the hairdresser. Precisely because the man she visited was not indifferent to her, her leaving is such that in leaving she is still present, more present, and ever the more present. While leaving, she is still with the man so much so that the purse is not there at all. In this kind of leaving, the purse was left behind because even while being in the room, she was with her friend so much that the purse was not there at all. At that tune there was no leaving-for-somewhere.
If the same woman were to leave someone to whom she was indifferent in order to go shopping in the city, then she would not forget the purse. Rather, she would take it with her because the purse belongs to shopping, to the relationship in which the woman would actually be involved. Here, the leaving is a leaving for the city. Only leaving for the city matters here. This having been with the acquaintance to whom she is indifferent is finished.
The matter [attributed to] unconscious intention is an explanation as opposed to a phenomenological interpretation. This explanation is a pure hypothesis that in no way advances the understanding of the phenomenon itself and, as such, of leaving [the purse] behind.
In the Freudian hypothesis leaving [the purse] behind is stressed as a fact which must then be explained. We ascertain this fact of leaving [the purse] behind from the outside. The woman herself does not leave the purse behind unconsciously because the purse is not there [for her] at all, and one can only leave something behind when it is there.
Pp. 168-9