occasions us more frequently to compare our present situation with the
parts of time or place, which are before and behind us.

So when we are enveloped in deep contemplation of any kind, or in reverie,
as in reading a very interesting play or romance, we measure time very
inaccurately; and hence, if a play greatly affects our passions, the
absurdities of passing over many days or years, and or perpetual changes of
place, are not perceived by the audience; as is experienced by every one,
who reads or sees some plays of the immortal Shakespear; but it is
necessary for inferior authors to observe those rules of the [Greek:
pithanon] and [Greek: prepon] inculcated by Aristotle, because their works
do not interest the passions sufficiently to produce complete reverie.

Those works, however, whether a romance or a sermon, which do not interest
us so much as to induce reverie, may nevertheless incline us to sleep. For
those pleasurable ideas, which are presented to us, and are too gentle to
excite laughter, (which is attended with interrupted voluntary exertions,
as explained Sect. XXXIV. 1. 4.) and which are not accompanied with any
other emotion, which usually excites some voluntary exertion, as anger, or
fear, are liable to produce sleep; which consists in a suspension of all
voluntary power. But if the ideas thus presented to us, and interest our
attention, are accompanied with so much pleasurable or painful sensation as
to excite our voluntary exertion at the same time, reverie is the
consequence. Hence an interesting play produces reverie, a tedious one
produces sleep: in the latter we become exhausted by attention, and are not
excited to any voluntary exertion, and therefore sleep; in the former we
are excited by some emotion, which prevents by its pain the suspension of
volition, and in as much as it interests us, induces reverie, as explained
in the next Section.