And our idea of the position of this last in time, like that of an object in space, is one of a relation to our present position, and is determined by the length of the sequence of experiences thus run over by the imagination.[115] It may be added that since the imagination can much more easily follow the actual order of experience than conceive it as reversed, the retrospective act of memory naturally tends to complete itself by a return movement forwards from the remembered event to the present moment.
In practice this detailed retracing of successive moments of mental life is confined to very recent experiences.

If I try to localize in time a remote event, I am content with placing it in relation to a series of prominent events or landmarks which serves me as a rough scheme of the past.

The formation of such a mnemonic framework is largely due to the needs of social converse, which proceeds by help of a common standard of reference.

This standard is supplied by those objective, that is to say, commonly experienced regularities of succession which constitute the natural and artificial divisions of the years, seasons, months, weeks, etc.

The habit of recurring to these fixed divisional points of the past renders a return of imagination to any one of them more and more easy.