ng any period, and the retrospective sense which
survives the period, for these do not necessarily agree. The former
rests mainly on our prospective sense of time, whereas the latter must
be altogether retrospective.[121]

Our estimate of time as it passes is commonly said to depend on the
amount of consciousness which we are giving to the fact of its
transition. Thus, when the mind is unoccupied and suffering from
_ennui_, we feel time to move sluggishly. On the other hand, interesting
employment, by diverting the thoughts from time, makes it appear to move
at a more rapid pace. This fact is shown in the common expressions which
we employ, such as "to kill time," and the German _Langweile_.
Similarly, it is said that when we are eagerly anticipating an event, as
the arrival of a friend, the mere fact of dwelling on the interval makes
it appear to swell out.[122]

This view is correct in the main, and is seen, indeed, to follow from
the great psychological principle that what we attend to exists for us
more, has more reality, and so naturally seems greater than what we do
not attend to. At the same time, this principle must be supplemented by
another consideration. Suppose that I am very desirous that time should
not pass quickly. If, for example, I am enjoying myself or indulging in
idleness, and know that I have to be off to keep a not very agreeable
engagement in a quarter of an hour, time will seem to pass too rapidly;
and this not because my thoughts are diverted from the fact of its
transition, for, on the contrary, they are reverting to it more than
they usually do, but because my wish to lengthen the interval leads me
to represent the unwelcome moment as further off than it actually is, in
other words, to construct an ideal representation of the period in
contrast with which the real duration looks miserably short.

Our estimate of duration, when it is over, depends less on this
circumstance of having attended to its transition than on other
considerations. Wundt, indeed, seems to think that the feeling
accompanying the actual flow of time has no effect on the surviving
subjective appreciation; but this must surely be an error, since our
mental image of any period is determined by the character of its
contents. Wundt says that when once a tedious waiting is over, it looks
short because we instantly forget the feeling of tedium. My
self-observation, as well as the interrogation of others, has satisfied
me, on