— 195 —
      §31. And thus I think it is plain, that from those two Fountains
of all Knowledge before mentioned, (viz.) Reflection and Sensation, we
get the Ideas of Duration, and the measures of it.
      For First, By observing what passes in our Minds, how our Ideas
there in train constantly some vanish, and others begin to appear,
we come by the Idea of Succession.
      Secondly, By observing a distance in the parts of this Succession,
we get the Idea of Duration.
      Thirdly, By Sensation observing certain appearances, at certain
regular and seeming equidistant periods, we get the Ideas of certain
Lengths or Measures of Duration, as Minutes, Hours, Days, Years,
etc.
      Fourthly, By being able to repeat those Measures of Time, or
Ideas of stated length of Duration in our Minds, as often as we will,
we can come to imagine Duration, where nothing does really endure or
— 196 —
exist; and thus we imagine to morrow, next year, or seven years
hence.
      Fifthly, By being able to repeat any such Idea of any length of
Time, as of a Minute, a Year, or an Age, as often as we will in our
own Thoughts, and add them one to another, without ever coming
to the end of such addition, any nearer than we can to the end of
Number, to which we can always add, we come by the Idea of
Eternity, as the future eternal Duration of our Souls, as well as the
Eternity of that infinite Being, which must necessarily have always
existed.
      Sixthly, By considering any part of infinite Duration, as set out by
periodical Measures, we come by the Idea of what we call Time in
general.
Locke Hum II, 14, §31, pp. 195-196