In Freud's work, "repeating" and "remembering" are "contrasting ways of bringing the past into the present."If past events are repressed from memory, they return in the present by expressing themselves in actions; when the subject does not remember the past, therefore, he is condemned to repeat it by acting it out.
"The patient does not remember anything of what he has forgotten and repressed, but acts it out. He reproduces it not as a memory, but as an action; he repeats it, without, of course, knowing that he is repeating it."
From a Lacanian perspective, this basic definition of "acting out" is true but incomplete; it ignores the dimension of the Other. Thus while Lacan maintains that acting out results from a failure to recollect the past, he emphasizes the intersubjective dimension of recollection. In other words, recollection does not merely involve recalling something to consciousness, but also communicating this to an Other by means of speech. Hence acting out results when recollection is made impossible by the refusal of the Other to listen.
When the Other has become "deaf," the subject cannot convey a message to him in words, and is forced to expressed the message in actions. The acting out is thus a ciphered message which the subject addresses to an Other, although the subject himself is neither conscious of the content of this message nor even aware that his actions express a message. It is the Other who is entrusted with deciphering the message; yet it is impossible for him to do so.