— 132 —
      §2. Thus the Idea of Heat and Cold, Light and Darkness, White
and Black, Motion and Rest, are equally clear and positive Ideas in
the Mind; though, perhaps, some of the causes which produce them,
are barely privations in those Subjects, from whence our Senses
derive those Ideas. These the Understanding, in its view of them,
considers all as distinct positive Ideas, without taking notice of the
Causes that produce them: which is an enquiry not belonging to the
Idea, as it is in the Understanding; but to the nature of the things
— 133 —
existing without us. These are two very different things, and care-
fully to be distinguished; it being one thing to perceive, and know
the Idea of White or Black, and quite another to examine what kind
of particles they must be, and how ranged in the Superficies, to
make any Object appear White or Black.
Locke Hum II, 8, §2, pp. 132-133