— 525 —
Knowledge is the Perception of the Agreement or Disagreement of two Ideas.
      §2. Knowledge then seems to me to be nothing but the perception of
the connexion and agreement, or disagreement and repugnancy of any of our
Ideas. In this alone it consists. Where this Perception is, there is
Knowledge, and where it is not, there, though we may fancy, guess,
or believe, yet we always come short of Knowledge. For when we
know that White is not Black, what do we else but perceive, that
these two Ideas do not agree? When we possess our selves with the
utmost security of the Demonstration, that the three Angles of a
Triangle are equal to two right ones, What do we more but perceive,
that Equality to two right ones, does necessarily agree to, and is
inseparable from the three Angles of a Triangle?
Locke Hum IV, 1, §2, p. 525