This distinction does not mean that memory differs from retention merely as a matter of temporal distance, the former reaching back further into time. Rather, Husserl draws a structural distinction between memory and retention: The former is an active, mediated, objectifying awareness of a past object, while the latter is a passive, immediate, non-objectifying, conscious awareness of the elapsed phase of conscious experience. First, memory reveals itself to be an act under the voluntary auspices of consciousness, whereas retention occurs passively. Second, while memories occur faster or slower and can be edited or reconstructed, retention occurs “automatically” and cannot be varied at one’s whim (though it can, at level 2, be experienced as faster or slower, as noted above in our example of listening to a lecture). Third, remembering re-produces a completed temporal object, whereas retention works at completing the consciousness of a temporal object, unifying its presence and absence. Fourth, as the representation of a new intentional object, memory is an act of presenting something as past, as absent, whereas the retention that attempts to account for the perception of an object over time constitutes an intuition of that which has just passed and is now in some sense absent, an act of presenting something as a unity in succession. Fifth, memory provides us with a new intentional object not now intuitively presented as the thing itself “in person”—e.g., remembering my friend’s face when she is absent from me in this moment—whereas retention accounts for the perception across time of an object now intuitively presented for me—e.g., the progressive clarity of my perception of my friends face as she approaches me from the street. Sixth, despite memory’s character as a presenting act, when it represents to me my friend’s face it represents it in the now with a change in temporal index or a qualification of the remembered object /as past/, whereas retention holds on to that which is related to my present perception in a mode of absences (e.g., as when I hear “picked” while retaining “Peter Piper”). Seventh, memory depends upon or is “founded” upon retention as the condition of its very possibility, for memory could never represent an object as a completed whole if retention did not first play its role in constituting across time the object now remembered (/PCIT/, No 50; Zahavi; Brough 1991.
[Phenomenology and Time-Consciousness | Internet Encyclopedia of Philosophy](http://www.iep.utm.edu/phe-time/)