— 188 —
The Revolutions of the Sun and Moon the properest Measures of Time.       §19. The diurnal, and annual Revolutions of the Sun, as having been
from the beginning of Nature, constant, regular, and universally
observable by all Mankind, and supposed equal to one another, have
been with Reason made use of for the measure of Duration. But the
distinction of Days and Years, having depended on the motion
of the Sun, it has brought this mistake with it, that it has been
thought, that Motion and Duration were the measure one of
another. For Men in the measuring of the length of time, having been
accustomed to the Ideas of Minutes, Hours, Days, Months, Years,
etc. which they found themselves upon any mention of Time or
Duration presently to think on, all which Portions of Time, were
measured out by the motion of those heavenly Bodies, they were apt
to confound time and motion; or at least to think, that they had
a necessary Connexion one with another: whereas any constant
periodical Appearance, or Alteration of Ideas in seemingly equi-
distant Spaces of Duration, if constant and universally observable,
would have as well distinguished the intervals of Time, as those
that have been made use of. For supposing the Sun, which some
have taken to be a Fire, had been lighted up at the same distance of
time that it now every Day comes about to the same Meridian, and
then gone out again about twelve hours after, and that in the Space
of an annual Revolution, it had sensibly increased in Brightness and
Heat, and so decreased again; would not such regular Appearances
serve to measure out the distances of Duration to all that could
observe it, as well without as with Motion? For if the Appearances
were constant, universally observable, and in equidistant Periods,
they would serve Mankind for measure of time as well, were the
Motion away.
Locke Hum II, 14, §19, p. 188